Electronic device, imaging device, and imaging element for obtaining exposure of each area of image

ABSTRACT

An electronic device includes: an imaging unit including a region having a pixel group that has a plurality of first pixels, and second pixels that are fewer than the first pixels in the pixel group; and a control unit that reads out the signals based upon exposure of the second pixels during exposure of the plurality of first pixels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Division of application Ser. No. 15/926,466 filed Mar. 20,2018, which in turn is a Division of application Ser. No. 15/038,744filed Dec. 20, 2016, which in turn is a National Stage ofPCT/JP2014/081275 filed Nov. 26, 2014, which claims the benefit ofJapanese Patent Application No. 2014-007869 filed Jan. 20, 2014 andJapanese Patent Application No. 2013-243946 filed Nov. 26, 2013. Thedisclosure of the prior applications are hereby incorporated byreference herein in their entireties.

TECHNICAL FIELD

The present invention relates to an electronic device, to an imagingdevice, and to an imaging element.

BACKGROUND ART

An electronic device that incorporates an imaging element in which animage capture chip of the backside-illumination type and a signalprocessing chip are laminated together (hereinafter, such an imagingelement will be termed a “laminated type imaging element”) has beenproposed (for example, refer to Patent Document #1). In such a laminatedtype imaging element, the backside-illumination type image capture chipand the signal processing chip are laminated together so as to beconnected via micro-bumps into block units each consisting of aplurality of pixels.

Furthermore, an imaging device is per se known (refer to Patent Document#2) in which a photoelectric conversion unit for image acquisition and aphotoelectric conversion unit for luminance evaluation are provided toan imaging element, and in which an image signal is output from thephotoelectric conversion unit for image acquisition when the totalsummed value of signals that are repeatedly output from thisphotoelectric conversion unit for luminance evaluation reaches apredetermined value.

CITATION LIST Patent Literature

Patent Document #1: Japanese Laid-Open Patent Publication 2006-49361.

Patent Document #2: Japanese Laid-Open Patent Publication 2012-204938.

SUMMARY OF INVENTION Technical Problem

However, with an electronic device that is equipped with such a priorart laminated type imaging element, there have not been many proposalsfor acquisition of images by capturing images with the plurality ofblock units, and, for example, if image capture of a still image or of amovie image or the like is performed by using the entire area of theimage capture region, then it has been difficult to generate an imagefor display. Due to this, the convenience of use of an electronic deviceequipped with a laminated type imaging element has not been adequate.

Furthermore, with a prior art imaging device, it has been difficult toapply this structure to a case in which the image is divided into blockseach having one or two or more of the regions described above and acaptured image for each of these blocks is acquired.

Solution to Technical Problem

According to the 1st aspect of the present invention, an electronicdevice comprises: an imaging unit including a region having a pixelgroup that has a plurality of first pixels, and second pixels that arefewer than the first pixels in the pixel group; and a control unit thatreads out the signals based upon exposure of the second pixels duringexposure of the plurality of first pixels.

According to the 2nd aspect of the present invention, the electronicdevice according to the 1st aspect may further comprise: a first readoutunit that reads out signals from the plurality of first pixels in thepixel group; and a second readout unit that reads out signals from thesecond pixels.

According to the 3rd aspect of the present invention, it is preferredthat in the electronic device according to the 1st or 2nd aspect, theimaging unit includes plurally the regions.

According to the 4th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 1st through3rd aspects, the control unit displays signals read out from the secondpixels upon a display unit.

According to the 5th aspect of the present invention, it is preferredthat in the electronic device according to the 4th aspect, the imagedisplayed upon the display unit is a live view image.

According to the 6th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 1st through3rd aspect, the control unit controls an exposure time interval of theplurality of first pixels based upon the signals read out from thesecond pixels.

According to the 7th aspect of the present invention, it is preferredthat in the electronic device according to the 6th aspect, the controlunit controls the exposure time interval of the plurality of firstpixels based upon a luminance obtained from the signals read out fromthe second pixels.

According to the 8th aspect of the present invention, an electronicdevice comprises: an imaging unit including a first region having aplurality of pixels, and a second region having at least a single pixelfewer than in the first region; and a control unit that reads out asignal based upon exposure of the pixels in the second region duringexposure of the plurality of pixels in the first region.

According to the 9th aspect of the present invention, the electronicdevice according to the 8th aspect may further comprise: a first readoutunit that reads out signals from the plurality of first pixels in thefirst region; and a second readout unit that reads out signals from thepixels in the second region.

According to the 10th aspect of the present invention, it is preferredthat in the electronic device according to the 8th or 9th aspect, theimaging unit has plurally the first regions and plurally the secondregions.

According to the 11th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 8th through10th aspects, the control unit displays signals read out from the pixelsin the second region upon a display unit.

According to the 12th aspect of the present invention, it is preferredthat in the electronic device according to the 11th aspect, the imageupon the display unit is a live view image.

According to the 13th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 8th through10th aspect, the control unit controls an exposure time interval of theplurality of pixels in the first region based upon the signals read outfrom the pixels in the second region.

According to the 14th aspect of the present invention, it is preferredthat in the electronic device according to the 13th aspect, the controlunit controls the exposure time interval of the plurality of firstpixels based upon a luminance obtained from the signals read out fromthe pixels in the second region.

According to the 15th aspect of the present invention, an electronicdevice comprises: an imaging unit that is capable of capturing an imagefrom a first region and an image from monitoring regions that areplurally arranged separately along a first direction and along a seconddirection, with each of the monitoring regions being smaller than thefirst region; and a control unit that makes timing at which chargesaccumulated in the first region are read out and timing at which chargesaccumulated in the monitoring region are read out be different.

According to the 16th aspect of the present invention, it is preferredthat in the electronic device according to the 15th aspect, the controlunit performs reading out of charge accumulated in the monitoring regionin case that reading out of the first region cannot be performed.

According to the 17th aspect of the present invention, it is preferredthat in the electronic device according to the 15th or 16th aspect, thecontrol unit performs reading out of charge accumulated in themonitoring region during a reset of the first region.

According to the 18th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 15th through17th aspects, the imaging unit captures an image of a light flux passedthrough an image capture optical system; and a focus detection pixelthat, provided in the monitoring region, detects the focal point of theimage capture optical system.

According to the 19th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 15th through18th aspects, the monitoring region has R pixels, G pixels, and Bpixels.

According to the 20th aspect of the present invention, the electronicdevice according to any one of the 15th through 19th aspects may furthercomprise: a display device that is capable of displaying a first imagethat is captured by the first region and a second image that is capturedby the monitoring region.

According to the 21st aspect of the present invention, the electronicdevice according to the 20th aspect may further comprise: a display unitthat, while the electronic device is performing long timing photography,displays upon the display device a second image that is captured by themonitoring region.

According to the 22nd aspect of the present invention, the electronicdevice according to the 20th aspect may further comprise: a displaycontrol unit that displays a second image that is captured by themonitoring unit as superimposed upon the first image that is beingdisplayed upon the display device.

According to the 23rd aspect of the present invention, it is preferredthat in the electronic device according to any one of the 15th through22nd aspects, each of the monitoring regions is disposed separately withregularity.

According to the 24th aspect of the present invention, it is preferredthat in the electronic device according to any one of the 15th through23rd aspects, the imaging unit is capable of capturing images from thefirst region and from a second region that is different from themonitoring region; and the electronic device may further comprise: animage capture control unit that is capable of setting image captureconditions individually for each of the first and second regions and themonitoring region.

According to the 25th aspect of the present invention, an imaging devicecomprises: an imaging unit in which a plurality of photoelectricconversion units are arranged; a control unit that subdivides theimaging unit into a plurality of area blocks each of which includes aplurality of the photoelectric conversion units, that controls thecharge accumulation time intervals of the photoelectric conversion unitsin units of the area blocks, and that is capable of reading outaccumulated signals in units of the area blocks; and a first monitoringsensor and a second monitoring sensor that are disposed at least in thefirst area block and the second area block respectively, and that arecapable of reading out amounts of charge accumulation from thephotoelectric conversion units.

According to the 26th aspect of the present invention, it is preferredthat in the imaging device according to the 25th aspect, the firstmonitoring sensor and the second monitoring sensor are constituted byphotoelectric conversion units, upon which green colored filters aredisposed, within the first area block and within the second area block.

According to the 27th aspect of the present invention, it is preferredthat in the imaging device according to the 25th or 26th aspect, thefirst monitoring sensor and the second monitoring sensor are arranged inapproximate centers of the first area block and the second area block.

According to the 28th aspect of the present invention, it is preferredthat in the imaging device according to any one of the 25th through 27thaspects, in case that the amount of charge accumulation by the firstmonitoring sensor reaches a predetermined amount of accumulation, thecontrol unit ends the charge accumulation by the photoelectricconversion units included in the corresponding first area block.

According to the 29th aspect of the present invention, it is preferredthat in the imaging device according to the 28th aspect, in case thatthe amount of charge accumulation by the second monitoring sensorreaches a predetermined amount of accumulation, the control unit endsthe charge accumulation by the photoelectric conversion units includedin the corresponding second area block.

According to the 30th aspect of the present invention, it is preferredthat in the imaging device according to the 28th or 29th aspect, thecontrol unit reads out the accumulated signals from the photoelectricconversion units in which the charge accumulation has ended by units ofthe area blocks.

According to the 31st aspect of the present invention, it is preferredthat in the imaging device according to the 28th aspect, the controlunit reads out the amount of charge accumulation from the firstmonitoring sensor and from the second monitoring sensor in response torelease actuation.

According to the 32nd aspect of the present invention, it is preferredthat in the imaging device according to the 29th aspect, for a thirdarea block that does not include either the first monitoring sensor orthe second monitoring sensor, the control unit ends the chargeaccumulation by the photoelectric conversion units included in the thirdarea block on the basis of the amount of charge accumulation of at leastone of the first monitoring sensor and the second monitoring sensor.

According to the 33rd aspect of the present invention, it is preferredthat in the imaging device according to the 25th aspect, the firstmonitoring sensor and the second monitoring sensor are constituted by aplurality of the photoelectric conversion units, upon which colorfilters of different colors are disposed, within the first area blockand within the second area block.

According to the 34th aspect of the present invention, it is preferredthat in the imaging device according to the 33rd aspect, in case thatthe amount of charge accumulation of the first monitoring sensor reachesthe predetermined amount of accumulation, the control unit ends thecharge accumulation by the photoelectric conversion, which has a colorfilter with the same color as the color filter of the first monitoringsensor is disposed, among the photoelectric conversion units included inthe first area block.

According to the 35th aspect of the present invention, an imagingelement in which a plurality of photoelectric conversion units isarrayed in an imaging unit, wherein: charge accumulation time intervalsof the photoelectric conversion units can be controlled in units of aplurality of area block into which the imaging unit is subdivided sothat the photoelectric conversion units are plurally included in thearea block; the signals accumulated in the photoelectric conversionunits can be read out in units of the area block; a first monitoringsensor and a second monitoring sensor are provided to at least a firstarea block and to a second area block respectively; and an amount ofcharge accumulation obtained by the photoelectric conversion units inthe first area block, and an amount of charge accumulation obtained bythe photoelectric conversion units in the second area block, can be readout from the first monitoring sensor and from the second monitoringsensor, respectively.

Advantageous Effects of Invention

According to the first aspect of the present invention, it is possibleto provide an electronic device whose convenience of use is good.Moreover, according to another aspect of the present invention, anappropriate exposure is obtained for each area of the image.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing an imaging element according to anembodiment;

FIG. 2 is a figure for explanation of an arrangement of pixels on animage capture chip and of unit groups thereof;

FIG. 3 is a circuit diagram corresponding to a unit group of the imagecapture chip;

FIG. 4 is a block diagram showing the functional structure of thisimaging element;

FIG. 5 is a figure showing a block region and a plurality of regionswithin that block region;

FIG. 6 is a horizontal sectional view showing the general structure of adigital camera that is one example of an electronic device;

FIG. 7 is a block diagram showing the structure of a digital cameraaccording to an embodiment;

FIG. 8 is a flow chart for explanation of an example of photographicoperation according to an embodiment;

FIG. 9 is a figure showing an example of a screen that is displayed upona display unit;

FIG. 10 is a flow chart for explanation of another example ofphotographic operation according to an embodiment;

FIG. 11 is a figure showing an example of a screen that is displayedupon the display unit;

FIG. 12 is a figure showing a plurality of regions within a block regionaccording to a variant embodiment;

FIG. 13 is a sectional view of a laminated type imaging element;

FIG. 14 is a figure for explanation of a pixel array and unit blocksupon an image capture chip;

FIG. 15 is a circuit diagram for explanation of the blocks upon theimage capture chip;

FIG. 16 is a block diagram showing the functional structure of theimaging element;

FIG. 17 is a figure for explanation of the flow of the pixel signal forone pixel;

FIG. 18 is a block diagram showing an example of the structure of animaging device that includes the above imaging element;

FIG. 19 is a figure for explanation of the arrangement of a plurality ofpixels in a block;

FIG. 20 is a figure showing, for a block, the relationship between thepixel positions and their pixel signal levels;

FIG. 21 is a figure for explanation of read out timings, chargeaccumulation time intervals, and pixel signals read out from the imagingelement via a calculation circuit;

FIG. 22 is a figure for explanation of normalization processing; and

FIG. 23 is a flow chart for explanation of the flow of photographicoperation executed by a control unit.

DESCRIPTION OF EMBODIMENTS Embodiment #1

In the following, a first embodiment of the present invention will beexplained with reference to the drawings. However, the present inventionis not to be considered as being limited thereby. Moreover, in thedrawings, in some cases, in order to explain the embodiment, the scaleof some portions may be changed by showing them as enlarged oraccentuated or the like. It should be understood that, in the followingembodiments, a lens interchangeable type digital camera will be cited asan example of an electronic device.

FIG. 1 is a sectional view showing an example of an imaging element 100.As shown in FIG. 1 , this imaging element 100 comprises an image capturechip 113 that outputs pixel signals corresponding to incident light, asignal processing chip 111 that processes pixel signals output from theimage capture chip 113, and a memory chip 112 that stores pixel signalsthat have been processed by the signal processing chip 111. The imagecapture chip 113, the signal processing chip 111, and the memory chip112 are laminated together. And the image capture chip 113 and thesignal processing chip 111 are electrically connected together byelectrically conductive bumps 109 a, 109 b that are made from Cu or thelike. Moreover, the signal processing chip 111 and the memory chip 112are electrically connected together by electrically conductive bumps 109c, 109 d that are made from Cu or the like.

In the following explanation of the imaging element 100, reference ismade to a rectangular XYZ coordinate system that is set up as shown inFIG. 1 , and the positional relationships of the various parts will beexplained with reference to this rectangular XYZ coordinate system.Here, the direction in which the light is incident is taken as being theZ-axis direction, one direction within a plane orthogonal to this Z-axisdirection is taken as being the X-axis direction, and the directionwithin this plane that is orthogonal to that X-axis direction is takenas being the Y-axis direction. It should be understood that thecoordinate axes of FIG. 1 are employed as reference in FIG. 2 and insome of the subsequent figures, and that these coordinate axes are shownso that the orientations of the various figures can be determined.

The example of an image capture chip 13 in this example is an MOS imagesensor of the backside-illumination type. A PD layer 106 is disposed onthe rear surface of a wiring layer 108. This PD layer 106 comprises aplurality of photodiodes 104 (herein abbreviated as “PD”s) that arearranged in a two-dimensional array and that accumulate electric changeaccording to incident light, and transistors 105 that are provided tocorrespond to these PDs 104.

Color filters 102 are provided upon the light-incident side of the PDlayer 106 with a passivation layer 103 interposed between them. Thesecolor filters 102 are filters that pass specified wavelength regions ofvisible light. The color filters 102 are of a plurality of types thatpass mutually different wavelength bands, and are disposed in a specificarrangement that corresponds to the arrangement of the PDs 104. Thearrangement of the color filters 102 will be explained hereinafter. Eachgroup including one of the color filters 102, one of the PDs 104, andone of the transistors 105 constitutes one pixel.

Micro-lenses 101 are provided upon the sides of the color filters 102upon which light is incident, and correspond to the abovementionedpixels. These micro-lenses 101 condense the incident light upon theircorresponding PDs 104.

The wiring layer 108 includes wiring 107 that transmits the pixelsignals from the PD layer 106 to the signal processing chip 111. Thiswiring 107 may be multi-layered, and also could be provided with passiveelements and active elements. A plurality of bumps 109 a are disposedupon the front surface of the wiring layer 108. This plurality of bumps109 a are positionally aligned with a plurality of bumps 109 b that areprovided on the opposing face of the signal processing chip 111. And thebumps 109 a and the corresponding bumps 109 b that are positionallyaligned therewith are joined together and are electrically connectedtogether by the image capture chip 113 and the signal processing chip111 being pressurized together, or the like.

In a similar manner, pluralities of bumps 109 c and 109 d are disposedupon the mutually opposing faces of the signal processing chip 111 andof the memory chip 112. The bumps 109 c and the bumps 109 d are mutuallypositionally aligned. And the bumps 109 c and the corresponding bumps109 d that are positionally aligned therewith are joined together andare electrically connected together by the signal processing chip 111and the memory chip 112 being pressurized together, or the like.

It should be understood that the joining between the bumps 109 a and thebumps 109 b, and the joining between the bumps 109 c and the bumps 109d, is not limited to being Cu bump joining by solid phase diffusion; itwould also be acceptable to arrange to employ micro-bump connection bysolder melting. Furthermore, for example, it would also be possible toprovide at least one set of bumps 109 a through 109 d for a single unitgroup that will be described hereinafter. Accordingly, it would beacceptable for the sizes of the bumps 109 a through 109 d to be set tobe larger than the pitch of the PDs 104. Moreover it would also bepossible, in peripheral regions other than the pixel region in whichpixels are disposed (i.e. the image capture region 114 shown in FIG. 1), to provide larger bumps than the bumps 109 a through 109 dcorresponding to the pixel region.

The signal processing chip 111 has a TSV 110 (Through-Silicon Via) thatmutually connects together circuits provided upon its front surface andupon its rear surface respectively. This TSV 110 is provided at aperipheral region. Moreover, such a TSV 110 may be provided at aperipheral region of the image capture chip 113 and/or at an edge regionof the memory chip 112.

FIG. 2 is a figure for explanation of the arrangement of pixels on theimage capture chip 113, and for explanation of unit groups of thosepixels. In FIG. 2 , a situation is shown in which the image capture chip113 is viewed from its rear surface side (i.e. its surface in the ⁻Zdirection).

As shown in FIG. 2 , an image capture region 114 is provided upon theimage capture chip 113. A plurality (for example, 20,000,000 or more)pixels P are arranged in this image capture region 114 in a matrixconfiguration along the X direction and the Y direction. In thefollowing, the direction along the X direction in which the pixels P arearranged will be termed the “first direction D1”, while the directionalong the Y direction will be termed the “second direction D2”.

An enlarged view of part of the image capture region 114 is shown in aportion of FIG. 2 . As shown in this partially enlarged view, redcolored pixels Pr (i.e., R pixels), green colored pixels Pg (i.e. Gpixels), and blue colored pixels Pb (i.e. B pixels) are included in theimage capture region 114. These three types of pixels P (i.e. the redcolored pixels Pr, the green colored pixels Pg, and the blue coloredpixels Pb) are arranged so as to form a so-called Bayer array.

The red colored pixels Pr are pixels having red colored filters as theircolor filters 102. Thus, these red colored pixels Pr receive light inthe red colored wavelength band. The green colored pixels Pg are pixelshaving green colored filters as their color filters 102. Thus, thesegreen colored pixels Pg receive light in the green colored wavelengthband. And the blue colored pixels Pb are pixels having blue coloredfilters as their color filters 102. Thus, these blue colored pixels Pbreceive light in the blue colored wavelength band.

As shown in FIG. 2 , in the image capture region 114, four adjacentpixels in a 2B2 arrangement constitute a single unit group 131. As anexample, in FIG. 2 , a single red colored pixel Pr, two green coloredpixels Pg, and a single blue colored pixel Pb are included in each unitgroup 131. It should be understood that the number of pixels that makeup each unit group 131 is not particularly limited; for example, itwould also be acceptable to arrange for sixteen adjacent pixels in a 4B4arrangement to constitute a single unit group 131, or for 1024 adjacentpixels in a 32B32 arrangement to constitute a single unit group 131.Moreover, it should be understood that the number of pixels that make upeach unit group 131 could also be greater than the above or less thanthe above.

FIG. 3 is a circuit diagram corresponding to one unit group 131 of theimage capture chip 113. In FIG. 3 , each rectangle surrounded by adotted line indicates a circuit that corresponds to a single pixel P. Itshould be understood that, in the following explanation, at least someof the transistors correspond to the transistors 105 of FIG. 1 .

As described above, the unit group 131 is formed from four pixels P.Each of the four PDs 104 that correspond respectively to these pixels Pis connected to a corresponding transfer transistor 302. TX wiring 307(a transfer section control line) that controls the transfer transistors302 is connected to the gate of each of these transfer transistors 302.Transfer pulses are supplied to this TX wiring 307. In this embodiment,the TX wiring 307 is connected to all of the four transfer transistors302 in common.

The drain of each of the transfer transistors 302 is connected to thesource of a corresponding reset transistor 303. And a so-called floatingdiffusion FD (i.e. a charge detection unit) is defined between the drainof each of the transfer transistors 302 and the source of thecorresponding reset transistor 303. This floating diffusion FD isconnected to the gate of an amplification transistor 304.

The drain of each of the reset transistors 303 is connected to Vddwiring 310. Power supply voltage is supplied to this Vdd wiring 310. Andthe gate of each of the reset transistors 303 is connected to resetwiring 306. Reset pulses are supplied to this reset wiring 306. In thisembodiment, the reset wiring 306 is connected to all of the four resettransistors 303 in common.

The drain of each of the amplification transistors 304 is connected tothe Vdd wiring 310 described above. Moreover, the source of each of theamplification transistors 304 is connected to the drain of thecorresponding one of the selection transistors 305.

The gate of each of the selection transistors 305 is connected todecoder wiring 308. Selection pulses are supplied to this decoder wiring308. In this embodiment, the decoder wiring 308 is provided to each ofthe four selection transistors 305 independently. The sources of theselection transistors 305 are connected to output wiring 309 in common.

A load current source 311 supplies current to the output wiring 309. Inother words, the output wiring 309 for the selection transistors 305 isconstituted by a source follower. It should be understood that this loadcurrent source 311 could also be provided on the side of the imagecapture chip 113, or on the side of the signal processing chip 111.

Now, the flow of operation from the start of charge accumulation untilpixel output after accumulation has ended will be explained. A resetpulse is supplied to the reset transistor 303 via the reset wiring 306.Simultaneously therewith, a transfer pulse is supplied to the transfertransistor 302 via the TX wiring 307. Due to this, the potentials of thePD 104 and of the floating diffusion FD are reset.

When supply of the transfer pulse to the PD 104 is cancelled, theincident light is converted to electrical charge and is accumulated.And, when subsequently a transfer pulse is supplied for a second time inthe state in which no reset pulse is being supplied, the charge that hasbeen accumulated by the PD 104 is transferred to the floating diffusionFD, and reading out of this charge is performed. Due to this, thepotential of the floating diffusion FD changes from the reset potentialto the signal potential after charge accumulation. And, when a selectionpulse is supplied to the selection transistor 305 via the decoder wiring308, change of the signal potential of the floating diffusion FD istransmitted to the output wiring 309 via the amplification transistor304 and the selection transistor 305. Due to this type of operation ofthe circuits, a pixel signal corresponding to the reset potential and tothe signal potential is output from this unit pixel to the output wiring309.

As shown in FIG. 3 , in this embodiment, the reset wiring 306 and the TXwiring 307 are provided in common for the four pixels P that make up theunit group 131. Due to this, the reset pulse and the transfer pulse areapplied simultaneously to all of these four pixels P. Accordingly, allof the pixels P that make up the unit group 131 start accumulation ofcharge at the same timing and stop accumulation of charge at the sametiming. However, due to the fact that the selection pulses are appliedsequentially to each of the selection transistors 305, the pixel signalscorresponding to the charges that have been accumulated are sequentiallyoutput in series to the output wiring 309 for each pixel P. Moreover,the reset wiring 306, the TX wiring 307, and the output wiring 309 areprovided separately for each of the unit groups 131.

It is possible to control the charge accumulation interval for each ofthe unit groups 131 by building the circuitry while taking the unitgroups 131 as reference in this manner. And, for different ones of theunit groups 131, it is possible to output pixel signals based uponcharge accumulation intervals that are mutually different. Furthermore,while charge accumulation is being performed one time for one of theunit groups 131, by repeating charge accumulation for another unit group131 any appropriate number of times and by outputting pixel signals eachtime, it is possible to output frames for video use at frame rates thatare different between these unit groups 131.

FIG. 4 is a block diagram showing the functional structure of thisimaging element. An analog multiplexer 411 selects the four PDs 104 thatmake up the unit group 131 in order. And the multiplexer 411 outputspixel signals from each of these four PDs 104 to the output wiring 309that is provided corresponding to that unit group 131. The multiplexer411 is formed upon the image capture chip 113 along with the PDs 104.

The analog pixel signals output via the multiplexer 411 are amplified byan amp 412 that is formed upon the signal processing chip 111. And bothcorrelated double sampling signal processing and A/D conversion(conversion from analog signals to digital signals) are performed uponthese pixel signals that have been amplified by the amp 412 by a signalprocessing circuit 413 that is formed upon the signal processing chip111 and that performs correlated double sampling (CDS) and analog todigital (analog/digital) conversion. Noise in the pixel signals isreduced by correlated double sampling signal processing being performedupon the pixel signals by the signal processing circuit 413. After theabove described A/D conversion, the pixel signals are forwarded to ademultiplexer 414, and are stored in pixel memories 415 that correspondto each pixel. The demultiplexer 414 and the pixel memories 415 areformed upon the memory chip 112.

A calculation circuit 416 performs processing upon the pixel signalsstored in the pixel memories 415 and transfers the result to a imageprocessing unit in a subsequent stage. This calculation circuit 416 maybe provided upon the signal processing chip 111, or may be provided uponthe memory chip 112. It should be understood that while, in FIG. 4 , theconnections of a single unit group 131 are shown, actually suchconnections are provided for each of the unit groups 131, and they alloperate in parallel. However, it would also be possible for calculationcircuits 416 not to be present for each of the unit groups 131. Forexample, it would also be acceptable to arrange for the processing to beperformed sequentially by a single calculation circuit 416 which refersto the values in the pixel memories 415 corresponding to each of theunit groups 131 in order.

As described above, output wiring 309 is provided to correspond to eachof the unit groups 131. In this imaging element 100, the image capturechip 113, the signal processing chip 111, and the memory chip 112 arelaminated together. Due to this, it is possible to route the wiringwithout making the chips large in their surface directions by employingelectrical connections between the chips using the bumps 109 for theoutput wiring 309.

FIG. 5 is a figure showing an example of the image capture region 114,for which control of various types is performed by a system control unit70 (an image capture control unit 72) that will be describedhereinafter. As shown in FIG. 5 , the image capture region 114 ispartitioned into a plurality of block regions 115. For example, each ofthese block regions 115 may be formed as rectangular. The plurality ofblock regions 115 are arranged so that a plurality thereof are arrangedalong a first direction D1 of the image capture region 114 and also aplurality thereof are arranged along a second direction D2 of the imagecapture region. While each of the block regions is set to be of the samearea and of the same shape, this is not to be construed as beinglimitative; they could be set to any desired areas and shapes. At leasta single unit group 131 is included in each of the block regions 115.Although, for example, in each of the block regions 115 the number ofpixels P and the arrangement of the red colored pixels Pr, the greencolored pixels Pg, and the blue colored pixels Pb are the same, thisalso is not to be construed as being limitative; it would be acceptableto arrange for the arrangement to be different between the various blockregions 115.

The system control unit 70 is capable of controlling the pixels Pincluded in the image capture region 114 while employing controlparameters that are different for each of the block regions 115. Inother words, for the pixel groups that are included within some blockregion 115, and for the pixel groups that are included within some otherblock region 115, pixel signals for which the control parameters aredifferent are capable of being acquired. As such control parameters, forexample, the time interval for charge accumulation or the number oftimes of charge accumulation, the frame rate, the gain, the pixelsub-sampling ratio (i.e. the thinning down ratio), the number of rows orcolumns of pixel signals to be added together (i.e. the number of pixelsto be totaled), the number of bits for digitization, and so on may becited. Furthermore, such control parameters could also be parameters forthe image processing that is performed after acquisition of imagesignals from the pixels.

A first region 115 a and a monitoring region 115 b are established ineach of the block regions 115. The first regions 115 a and themonitoring regions 115 b are regions that are set up so that reading outof their charges at mutually different timings is possible. Each of thefirst regions 115 a and each of the monitoring regions 115 b is set soas to include one or more pixels P. The monitoring regions 115 b are setso as to be smaller than the first regions 115 a. In this case, thenumber of pixels P included in each of the monitoring regions 115 b islower than the number of pixels P included in the corresponding firstregion 115 a.

For example, a monitoring region 115 b may consist of a single unitgroup 131. Accordingly, four pixels P are included in this monitoringregion 115 b: one red colored pixel Pr, two green colored pixels Pg, andone blue colored pixel Pb. Since one or more red colored pixels Pr, oneor more green colored pixels Pg, and one or more blue colored pixels Pbare included in each of the monitoring regions 115 b in this manner,accordingly it is possible to obtain a full color image when imagecapture is performed using only the monitoring regions 115 b. Moreover,among the plurality of pixels P that are included in the block regions115, the first regions 115 a includes pixels P other than the pixels Pthat are included in the monitoring regions 115 b. For example, thefirst regions 115 a may be made up of a plurality of unit groups 131.

In this manner, each of the first regions 115 a and each of themonitoring regions 115 b is constituted by one or a plurality of unitgroups 131. In this embodiment, the system control unit 70 that will bedescribed hereinafter is capable of varying the reading out of chargefor each of the unit groups 131. Due to this, the system control unit 70becomes capable of making the timings at which the charges are read outbe different for the first regions 115 a and for the monitoring regions115 b. It should be understood that the format of the pixels P that areincluded in the first regions 115 a and in the monitoring regions 115 bis not to be considered as being limited to that described above; anyformat will be acceptable, provided that the system control unit 70 iscapable of making the timings at which the charges are read out bedifferent for the first regions 115 a and for the monitoring regions 115b. For example, the monitoring regions 115 b may be made up of aplurality of unit groups 131. Moreover, it would also be acceptable, forexample, to arrange for the first regions 115 a and the monitoringregions 115 b each to include a predetermined number of red coloredpixels Pr, green colored pixels Pg, and blue colored pixels Pb, withoutany relationship to the unit groups 131.

In each of the block regions 115, among the four corner portions of theblock region 115, the monitoring region 115 b may, for example, bearranged at the corner portion at the +X side and the +Y side. By doingthis, a plurality of the monitoring regions 115 b may be provided in theimage capture region 114. And each of the monitoring regions 115 b isarranged separately in a regular manner along the first direction D1 andthe second direction D2. It should be understood that the arrangement ofthe monitoring regions 115 b is not to be considered as being limited tothis type of configuration in which they are arranged in a regularmanner along the first direction D1 and the second direction D2.

Next, the control parameters will be explained. The time interval forcharge accumulation is the time period from when accumulation of chargeby a PD 104 starts until it stops. This charge accumulation interval isalso sometimes termed the exposure time or the shutter speed. Moreover,the number of times of charge accumulation is the number of times that aPD 104 accumulates charge in a unit time interval. And the frame rate isa value that, for a movie image, specifies the number of frames that areprocessed (i.e. displayed or recorded) in a unit time interval. The unitof frame rate is expressed as fps (Frames Per Second). The higher theframe rate becomes, the smoother the movement of the photographicsubject (in other words, of the subject whose image is being captured)in the movie becomes.

Furthermore, the gain is the gain ratio of the amps 412 (i.e., theiramplification ratio). By changing this gain, it is possible to changethe ISO speed. This ISO speed is a standard for photographic film thatis defined by ISO, and represents the lowest light level at which aphotographic film is capable of recording. However, generally, ISO speedis also used for expressing the sensitivity of an imaging element 100.In this case, the ISO speed is a value that represents the capability ofthe imaging element 100 for capturing light. If the gain is increased,then the ISO speed is also enhanced. For example, when the gain isdoubled, the signals (i.e. the pixel signals) also become doubled inmagnitude, so that, even if the amount of incident light is halved, itsbrightness is still adequate. However since, when the gain is increased,the noise included in the signal is also amplified, accordingly thenoise also becomes greater, and this is undesirable.

And further, the sub-sampling ratio is the proportion of the number ofpixels in some predetermined region for which reading out of the pixelsignals is not performed, with respect to the total number of pixels inthat region. For example, if the sub-sampling ratio in the predeterminedregion is zero, this means that reading out of the pixel signals fromall of the pixels in the predetermined region is performed. Moreover, ifthe sub-sampling ratio in the predetermined region is 0.5, this meansthat reading out of the pixel signals from half of the pixels in thepredetermined region is performed. For example, if the unit group 131 isa Bayer array, then it is possible to set every second pixel of theBayer array unit in the vertical direction, in other words each twopixels alternatingly (i.e. each two rows) of the pixel unit, as beingpixels whose signals are to be read out and pixels whose signals are notto be read out. It should be understood that the resolution of the imageis reduced when such sub-sampling by reading out pixel signals is beingperformed. However, since 20,000,000 or more pixels are disposed uponthe imaging element 100, accordingly, even if for example sub-samplingat a sub-sampling ratio of 0.5 is performed, it is still possible todisplay an image that is made up from 10,000,000 or more pixels.

Yet further, the number of rows to be added together is, if the pixelsignals of pixels that are adjacent in the vertical direction are to beadded together, the number of pixels in the vertical direction (i.e. thenumber of rows) to be employed in this addition. Moreover, the number ofcolumns to be added together is, if the pixel signals of pixels that areadjacent in the horizontal direction are to be added together, thenumber of pixels in the horizontal direction (i.e. the number ofcolumns) to be employed in this addition. This type of additionprocessing may, for example, be performed by the calculation circuit416. By the calculation circuit 416 performing processing to addtogether the pixel signals from a predetermined number of pixels thatare adjacent in the vertical direction or in the horizontal direction,the same type of beneficial effects are obtained as in the case ofprocessing to read out the pixel signals by sub-sampling at somepredetermined sub-sampling ratio. It should be understood that it wouldalso be acceptable, in the addition processing described above, toarrange for an average value to be calculated by dividing the totalvalue by the number of rows or the number of columns that have beenadded together by the calculation circuit 416.

And finally, the number of bits for digitization is the number of bitsthat is output when the analog signal is converted into a digital signalduring the A/D conversion performed by the signal processing circuit413. The greater is the number of bits in the digital signal, the fineris the detail for expressing changes of luminance or color or the like.

In this embodiment, the term “accumulation conditions” means conditionsthat are related to accumulation of charge by the imaging element 100.In concrete terms, the accumulation conditions include the chargeaccumulation time interval or the number of times of chargeaccumulation, the frame rate, and the gain among the control parametersdescribed above. Since the frame rate can change according to the chargeaccumulation time interval or the number of times of chargeaccumulation, therefore the frame rate is included in the accumulationconditions. Moreover, the amount of light that is appropriate forexposure changes according to the gain, and the charge accumulation timeinterval or the number of times of charge accumulation can also changeaccording to the amount of light that is appropriate for exposure. Dueto this, the gain is also included in the accumulation conditions.

Moreover, since the amount of light that is appropriate for exposurechanges according to the charge accumulation time interval or the numberof times of charge accumulation, the frame rate, and the gain,accordingly in some cases, in this embodiment, the accumulationconditions are alternatively termed “exposure conditions” (i.e.,conditions related to exposure).

Furthermore, in this embodiment, “image capture conditions” meansconditions relating to capture of an image of a photographic subject. Inconcrete terms, the image capture conditions are control parameters thatinclude the accumulation conditions described above. Apart from thecontrol parameters for controlling the imaging element 100 (for example,the charge accumulation time interval or the number of times of chargeaccumulation, the frame rate, and the gain), the image captureconditions also include control parameters for controlling reading outof the signals from the imaging element 100 (for example, thesub-sampling ratio and the number of rows or the number of columns whosepixel signals are to be added together) and control parameters forprocessing the signal from the imaging element 100 (for example, thenumber of bits for digitization, and control parameters referred to byan image processing unit 30 that will be described hereinafter in orderto perform image processing).

FIG. 6 is a horizontal sectional view showing the general structure of adigital camera 1 that is an example of an electronic device. And FIG. 7is a block diagram showing an example of this digital camera 1.

As shown in FIGS. 6 and 7 , the digital camera 1 of this embodimentcomprises a lens unit 10 and a camera body 2.

The lens unit 10 is an interchangeable lens. It should be understoodthat it would also be acceptable for the digital camera 1 not to includeany separate lens unit 10. I.e., the lens unit 10 could also be formedas an integral portion of the digital camera 1. In the state in whichthis lens unit 10 is connected to the camera body 2, it conducts a lightflux from a photographic subject to an imaging unit 20.

A lens side mounting portion 80 b is provided to the lens unit 10. Thislens side mounting portion 80 b is detachably installed to a body sidemounting portion 80 a that is provided to the camera body 2. The lensunit 10 is installed to the camera body 2 by the user joining the bodyside mounting portion 80 a and the lens side mounting portion 80 btogether. When the lens unit 10 is thus installed to the camera body 2,electrical contact points 81 a that are provided to the body sidemounting portion 80 a and electrical contact points 81 b that areprovided to the lens side mounting portion 80 b become electricallyconnected together.

The lens unit 10 comprises an image capture optical system 11, an irisaperture 14, and a lens drive control device 15. A lens 11 a, a lens 11b for zooming, and a lens 11 c for focusing are included in the imagecapture optical system 11. The lens drive control device 15 comprises alens side CPU (Central Processing Unit), a memory, and a drive controlcircuit. The lens drive control device 15 is electrically connected to asystem control unit 70 on the camera body 2 side via the electriccontact points 81 a and 81 b, and performs transmission of lensinformation related to the optical characteristics of the image captureoptical system 11 included in the lens unit 10 and reception of controlinformation for driving the zooming lens 11 b, the focusing lens 11 c,and the iris aperture 14.

On the basis of control information transmitted from the system controlunit 70, the lens side CPU of the lens drive control device 15 performscontrol for driving the focusing lens 11 c with a drive control circuit,in order to perform focus adjustment of the image capture optical system11. And, on the basis of control information transmitted from the systemcontrol unit 70, the lens side CPU of the lens drive control device 15performs control for driving the zooming lens 11 b with a drive controlcircuit, in order to perform zooming adjustment. Moreover, the irisaperture 14 is disposed upon the optical axis of the image captureoptical system 11. This iris aperture 14 defines an aperture that iscentered upon the optical axis and whose diameter can be varied in orderto adjust the amount of light and the amount of blurring. And, on thebasis of control information transmitted from the system control unit70, the lens side CPU of the lens drive control device 15 performscontrol for driving the iris aperture 14 with a drive control circuit,in order to perform adjustment of the diameter of the iris aperture 14.

Next, the camera body 2 comprises the imaging unit 20, an imageprocessing unit 30, a working memory 40, a display unit 50, an actuationunit 55, a recording unit 60, and the system control unit 70. As shownin FIG. 7 , the imaging unit 20 comprises an imaging element 100 and adrive unit 21. The imaging element 100 comprises an image capture region114 that photoelectrically converts a light flux emitted from the imagecapture optical system 11 of the lens unit 10 pixel by pixel, andthereby generates pixel signals (the pixel signals are included in imagedata). First regions 115 a and monitoring regions 115 b are included inthe image capture region 114. The imaging unit 20 is capable ofcapturing images in the first regions 115 a and in the monitoringregions 115 b.

The drive unit 21 is a control circuit that controls driving of theimaging element 100 according to commands from the system control unit70. Here, the drive unit 21 is capable of controlling the timings (orthe periods of the timings) at which reset pulses and transfer pulsesare supplied to the various reset transistors 303 and to the varioustransfer transistors 302 respectively. Due to this control, it ispossible to control the time interval for charge accumulation or thenumber of times of charge accumulation, which are control parameters,and also the timings at which the charges are read out. The drive unit21 can drive the first regions 115 a and the monitoring regions 115 bindependently of one another. Accordingly, it becomes possible to readout the charges from the first regions 115 a and from the monitoringregions 115 b at mutually different timings.

Furthermore, the drive unit 21 controls the frame rate by controllingthe timings (or the periods of the timings) at which the reset pulses,the transfer pulses, and the selection pulses are supplied to thevarious reset transistors 303, to the various transfer transistors 302,and to the various selection transistors 305 respectively. Moreover, thedrive unit 21 controls the sub-sampling ratio by setting the pixels towhich the reset pulses, the transfer pulses, and the selection pulsesare supplied.

Yet further, the drive unit 21 controls the ISO speed of the imagingelement 100 by controlling the gain of the amps 412. And, by sendingcommands to the calculation circuits 416, the drive unit 21 sets thenumber of rows or the number of columns for which the pixel signals areto be added together. Even further, by sending commands to the signalprocessing circuits 413, the drive unit 21 sets the number of bits fordigitization. Still further, in the image capture region 114 of theimaging element 100, the drive unit 21 sets regions by block units. Inthis manner, the drive unit 21 plays the role of an imaging elementcontrol unit that makes the imaging element 100 capture images andoutput pixel signals under image capture conditions that are mutuallydifferent for each of the plurality of blocks. And the system controlunit 70 issues commands to the drive unit 21 for specifying thepositions, shapes, ranges and so on of the blocks. It should beunderstood that the imaging unit 20 sends RAW data consisting of thepixel signal for each pixel to the image processing unit 30 (i.e., RAWdata is also included in the image data).

The image processing unit 30 performs image processing of various typesupon the RAW data consisting of the pixel signals that have beengenerated by the imaging unit 20, and generates image data in apredetermined file format (for example, the JPEG format or the like). Itshould be understood that in some cases “image data” means “imagesignal”. Moreover, still images, movie images, live view images, andpartial images are included in the meaning of the term “image”. Liveview images are images consisting of image data generated by the imageprocessing unit 30, which are output in series to the display unit 50and are displayed upon the display unit 50. Such live view images areemployed by the user in order to check the image of the photographicsubject that is being captured by the imaging unit 20. Live view imagesare also sometimes called “through images” or “preview images”.

Furthermore, the image processing unit 30 performs the following imageprocessing. For example, the image processing unit 30 may generate anRGB image signal by performing color signal processing (colorcompensation) upon the signal that has been obtained from the Bayerarray. Moreover, the image processing unit 30 may perform imageprocessing such as white balance adjustment, sharpness adjustment, gammacorrection, tone adjustment and so on upon this RGB image signal. Yetfurther, according to requirements, the image processing unit 30 mayperform processing to compress the RGB image signal according to somepredetermined compression format (such as the JPEG format, the MPEGformat, or the like). The image processing unit 30 outputs the imagedata that it has thus generated to the recording unit 60. Moreover, theimage processing unit 30 outputs the image data that it has thusgenerated to the display unit 50.

Parameters that are referred to by the image processing unit 30 whileperforming image processing are also included as control parameters(i.e., image capture conditions). For example, parameters for colorsignal processing (color compensation), white balance adjustment, toneadjustment, compression ratio, and so on are included as being controlparameters. The signal that is read out from the imaging element 100changes according to the charge accumulation time interval and so on,and the parameters that are referred to while performing imageprocessing also change according to change of this signal. The imageprocessing unit 30 sets control parameters that are mutually differentfor each of the block units, and performs image processing such assignal processing and so on based upon these control parameters.

In this embodiment, as shown in FIG. 7 , the image processing unit 30includes an image generation unit and a detection unit not shown in thefigures. The image generation unit generates image data by performingimage processing of various kinds upon the RAW data consisting of thepixel signals from the pixels output from the imaging unit 20. In thisembodiment, the image generation unit not only generates image data formovie images (including live view images) and for still images, but alsois capable of generating image data for partial view images as mentionedabove. And the detection unit detects the photographic subject from theimage data that has been generated by the image generation unit. In thisembodiment, the detection unit has the function of comparing together aplurality of sets of image data (i.e. frames) that have been obtainedsuccessively in time series from the image generation unit, and ofdetecting a photographic subject that shifts (i.e. a shiftingphotographic subject). Moreover, the detection unit has the function ofspecifying the boundary of the photographic subject on the basis ofchanges of contrast and/or color of light portions and dark portions inthe image data, and thereby detecting the photographic subject. Itshould be understood that it would also be acceptable to arrange for thedetection unit to detect human bodies included in the image data asphotographic subjects, as for example described in Japanese Laid-OpenPatent Publication 2010-16621 (US 2010/0002940).

Here, there is no limitation to the case in which only one photographicsubject captured by the imaging unit 20 is present in the image data; inother cases, a plurality thereof may be present. Furthermore, amongthese photographic subjects, the photographic subject that the user(i.e. the photographer) is giving his attention to, or that it isestimated that the user is giving his attention to, is termed the “mainphotographic subject”. There is also no limitation to the case in whichonly one main photographic subject is present in the image data; inother cases, a plurality thereof may be present.

The working memory 40 temporarily stores image data and so on whileimage processing is being performed by the image processing unit 30. Andthe display unit 50 displays images captured by the imaging unit 20(still images, movie images, live view images, and/or partial viewimages) and information of various kinds. This display unit 50 may, forexample, include a display panel 51 such as a liquid crystal displaypanel or the like. It would also be acceptable for a touch panel to beprovided upon the display panel 51 of the display unit 50. In this case,when the user performs actuation to select an item from a menu or thelike, the touch panel outputs to the system control unit 70 a signalspecifying the position that the user has touched.

The actuation unit 55 includes a release switch 55 a (i.e. a switch thatis pressed when photographing a still image) and a preview switch 55 b(i.e. a switch that is pressed when performing preview display of astill image or of a movie image) that are actuated by the user, a movieimage switch (a switch that is pressed during operation for moviephotography), and operating switches of various types and so on. Therelease switch 55 a is capable both of being half press actuated andbeing full press actuated. The preview switch 55 b may be set up upon atouch panel (not shown in the figures), or may be provided as a buttonupon the camera body 2. The actuation unit 55 outputs signals to thesystem control unit 70 corresponding to actuation by the user.

The recording unit 60 has a card slot in which a storage medium such asa memory card or the lot can be installed. This recording unit 60 storesimage data generated by the image processing unit 30 and data of variousother types upon a recording medium that is installed in the card slot.Moreover, the recording unit 60 has an internal memory. The recordingunit 60 is also capable of recording image data generated by the imageprocessing unit 30 and data of various other types in this internalmemory.

The system control unit 70 controls the overall processing and operationof the digital camera 1. This system control unit 70 includes a bodyside CPU (Central Processing Unit). Moreover, as shown in FIG. 7 , thesystem control unit 70 comprises a display control unit 71 and an imagecapture control unit 72. The display control unit 71 performs controlfor outputting image data that has been generated by the imageprocessing unit 30 to the display unit 50, and also performs control forcausing images (still images, movie images, live view images, and/orpartial view images) to be displayed upon the display panel 51 of thedisplay unit 50. The display control unit 71 can also cause a pluralityof such images to be displayed upon the display panel 51 as superimposedone over the another.

And the image capture control unit 72 sets image capture conditions forthe image capture region 114 of the imaging element 100 (i.e. controlparameters for color signal processing, white balance adjustment, toneadjustment, compression ratio, and so on). This image capture controlunit 72 is capable of setting image capture conditions separately andindividually for the first regions 115 a and for the monitoring regions115 b. Moreover, the image capture control unit 72 performs control forimage data generated by the image generation unit 31 for movie images,still images, and partial video images to be recorded by the recordingunit 60.

It should be understood that the system control unit 70 is capable ofacquiring images at different charge accumulation intervals (ordifferent numbers of times of charge accumulation), different framerates, and different gains for each one of the block regions 115 in theimage capture region 114 of the imaging element 100 (i.e. of the imagecapture chip 113). In this case, the system control unit 70 issuescommands to the drive unit 2 for specifying the positions, shapes,ranges of the blocks, and the accumulation conditions to be used foreach of the blocks. Moreover, the system control unit 70 may acquireimages at sub-sampling ratios, numbers of rows or of columns whose pixelsignals are to be added together, and numbers of bits for digitizationthat are different for each of the block regions 115. For doing this,the system control unit 70 issues commands to the drive unit 21 forspecifying the image capture conditions to be employed for each blockregion 115 (i.e. the sub-sampling ratio, the number of rows or ofcolumns whose pixel signals are to be added together, and the number ofbits for digitization). And the system control unit 70 issues commandsto the image processing unit 30 for specifying the image captureconditions to be employed for each block region 115 (i.e. conditions forcolor signal processing, white balance adjustment, tone adjustment,compression ratio, and so on).

Furthermore, the system control unit 70 causes the recording unit 60 torecord the image data that has been generated by the image processingunit 30. Moreover, by outputting to the display unit 50 image data thathas been generated by the image processing unit 30, the system controlunit 70 causes that image to be displayed upon the display unit 50. Yetfurther, by reading out image data recorded by the recording unit 60 andoutputting that image data to the display unit 50, the system controlunit 70 causes the corresponding image to be displayed upon the displayunit 50. Still images, movie images, live view images, and partial viewimages are included as images that can be displayed upon the displayunit 50.

Even further, on the basis of the fact that half press actuation of therelease switch 55 a has been performed, the control unit 70 performsfocus adjustment processing (i.e. AF processing) by a so-called contrastdetection method, so that the contrast of the photographic subjectbecomes maximum. In concrete terms, the system control unit 70 causesthe lens drive control device 15 to shift the focusing lens 11 c bytransmitting control information to the lens drive control device 15 viathe electric contact points 81 a, 81 b. Moreover, the system controlunit 70 acquires from the image processing unit 30 a contrast signalthat specifies the contrast of the image of the photographic subjectthat is being captured by the imaging unit 20 (here, if a mainphotographic subject has been detected by the image processing unit 30,then this is the evaluated value of the contrast of the image of thismain photographic subject). On the basis of this contrast signal fromthe image processing unit 30, while shifting the focusing lens 11 c, thesystem control unit 70 detects the position of the focusing lens 11 c atwhich the contrast of the image of the photographic subject becomes thehighest as being the focusing position. And the system control unit 70transmits a control signal to the lens drive control device 15 so as tocause the focusing lens 11 c to shift to this focus position that hasthus been detected.

The system control unit 70 also performs drive control for adjusting thediameter of the iris aperture 14 by transmitting to the lens drivecontrol device 15 control information specifying an iris aperture valuethat corresponds to an appropriate exposure. Moreover, the systemcontrol unit 70 also outputs a command signal to the drive unit 21 forspecifying a shutter speed (i.e. a charge accumulation interval), aframe rate, and a gain (i.e. an ISO speed) that correspond to thisappropriate exposure. And the drive unit 21 controls the driving of theimaging element 100 according to the shutter speed, the frame rate, andthe gain that are commanded by this command signal. It should beunderstood that the system control unit 70 is implemented by the bodyside CPU executing processing on the basis of a control program.

An Example of Photographic Operation

FIG. 8 is a flow chart for explanation of an example of the photographicoperation performed by the system control unit 70 of the firstembodiment. When the power supply to the digital camera 1 is turned onby the user and a predetermined actuation is performed upon theactuation unit 55 or the like in order to start photography, the systemcontrol unit 70 performs image capture operation with the imaging unit20. First, the system control unit 70 performs driving of the imagingelement 100 with the drive unit 21. On the basis of this control, thedrive unit 21 captures a live view image using both the first regions115 a and also the monitoring regions 115 b in the image capture region114 (step S1). In this step S1, the system control unit 70 performsaccumulation of charges in the first regions 114 a and in the monitoringregions 115 b and reading out of the accumulated charges at apredetermined frame rate. The pixel signals from the pixels P of thefirst regions 115 a and of the monitoring regions 115 b are output tothe image processing unit 30. Image data is generated from these pixelsignals by the image processing unit 30, and this image data is outputin series to the display unit 50. Due to this, as shown in FIG. 9(a), alive view image 151 is displayed upon the display panel 51 (step S2).For example, the face 52 of an animal may be captured as this live viewimage 151.

Next, the system control unit 70 determines with the image capturecontrol unit 72 whether or not half press actuation of the releaseswitch 55 a (i.e. actuation of a switch SW1) has been performed by theuser (step S3). If the system control unit 70 decides that half pressactuation has been performed (YES in step S3), then AF operation isperformed by employing a contrast detection method (step S4). The systemcontrol unit 70 is capable of displaying a display upon the displaypanel 51 in order for the user to select whether or not AF operation isto be performed. In this case, the system control unit 70 performs AFoperation if the user has performed actuation for AF operation to beperformed. It should be understood that, if the system control unit 70has determined that half press actuation of the release switch 55 a isnot being performed, then the flow of control returns back to step S3again, and the decision as to whether half press actuation has beenperformed is repeated. Moreover, it should be understood that it wouldalso be acceptable for AF operation not to be performed.

After AF operation has been performed, the system control unit 70determines with the image capture control unit 72 whether or not fullpress actuation of the release switch 55 a (i.e. actuation of a switchSW2) has been performed by the user (step S5). If the system controlunit 70 decides that full press actuation has been performed (YES instep S5), then image capture of a live view image is performed with themonitoring regions 115 b (step S6), and this live view image that hasthus been captured is displayed over the entire surface of the displaypanel 51 (step S7).

Due to this, the state of the display upon the display panel 51 changesover from the state in which the live view image 151 that is capturedboth with the first regions 115 a and with the monitoring regions 115 bis displayed upon the display panel 51, to the state in which a liveview image 152 that is captured only with the monitoring regions 115 bis displayed upon the display panel 51, as shown in FIG. 9(b). In thiscase, although the resolution on the display panel 51 becomes lower thanthat of the live view image 151 (refer to FIG. 9(a)), still the face 52a of the animal, which is the same subject, is displayed continually asthe live view image 152. It should be understood that, if the systemcontrol unit 70 has determined that full press actuation of the releaseswitch 55 a is not being performed (NO in step S5), then the flow ofcontrol returns back to step S5 again, and the decision as to whetherfull press actuation has been performed is repeated. At this time itwould also be acceptable, if full press actuation is not performedduring a predetermined time period after the end of AF operation, toarrange for the system control unit 70 to return the flow of controlback to step S3, so as to perform the operations of steps S3 through S5again.

Next, the system control unit 70 performs capture of a still image byusing the first regions 115 a (step S8). In this capturing of a stillimage, the system control unit 70 sets image capture conditions such asthe charge accumulation interval and so on for only the first regions115 a, and controls the drive unit 21 so as to perform image captureunder these image capture conditions that have thus been set. Due tothis, the charges that have been accumulated by the pixels P of thefirst regions 115 a are reset, and exposure of the first regions 115 ais performed and their charges are accumulated by the first region 115a. At this time, it would also be acceptable to arrange for the systemcontrol unit 70 to determine with the image capture control unit 72whether or not long timing photography is being performed by the user,and for AF operation to be continually performed if it is determinedthat long timing photography is being performed. In this case, forexample, by performing long timing photography of a photographic subjectthat is shifting, it is possible to implement AF operation so as totrack the photographic subject. It should be understood that the systemcontrol unit 70 may, for example, determine whether or not the chargeaccumulation interval that has been set is longer than somepredetermined threshold value (for example, 1 second), and may determinethat long timing photography is being performed if the chargeaccumulation interval is longer than this predetermined threshold value.Next, reading out of the charges accumulated by the pixels P isperformed, the pixel signals for the pixels P are generated, and thesepixel signals are transmitted to the image processing unit 30. Afterreading out of the charges that have been accumulated in the firstregions 115 a has been performed, reset signals are supplied to thepixels P in the first regions 115 a.

It should be understood that, while the image capture operationdescribed above is being performed, along with repeatedly performingaccumulation and reading out of charges at the predetermined frame ratefrom each of the monitoring regions 115 b, the system control unit 70also causes the live view image 152 captured by the monitoring regions115 b to be displayed upon the display panel 51 (refer to FIG. 9(b)).Accordingly, during the image capture operation, the live view image 152continues to be displayed upon the display panel 51.

For the regions in the image capture region 114 that are used forcapture of a still image, for example, reading out of charges ceases tobe possible in the interval in which the charges are being reset or thelike. Due to this, if for example capture of a still image were to beperformed by using the entire image capture region 114, then it wouldnot be possible to perform display of a live view image 151 during suchan interval in which the charges were being reset.

By contrast since, with this embodiment, the first regions 115 a areused for the operation of capturing a still image, and these onlyconstitute a portion of the image capture region 114, accordingly,during the interval in which the first regions 115 a are being reset,reading out of the charges in the first regions 115 a ceases to bepossible. On the other hand, reading out of charges independently fromthe first regions 115 a and the monitoring regions 115 b of the imagecapture region 114 is possible. Moreover, the system control unit 70 iscapable of making the timings of the reading out of the chargesaccumulated in the first regions 115 a and the timings of the readingout of the charges accumulated in the monitoring regions 115 b bedifferent from one another. Thus the system control unit 70 is able toperform the reading out of the charges accumulated in the monitoringregions 115 b when it is not possible to perform reading out of thecharges in the first region 115 a, as for example when the first regions115 a are being reset or the like as explained above. Due to this, thesystem control unit 70 is able to photograph the live view image 152 andto display it upon the display panel 51 by using only, for example, themonitoring regions 115 b. Accordingly, the system control unit 70 iscapable of displaying the live view image 152 without interruption, evenduring capture of a still image. Since the user is able to check thestate of the photographic subject on the display panel 51 even duringcapture of a still image, accordingly the convenience is enhanced whenperforming sequential shooting or the like. It should be understood thatit would also be acceptable, if the user is performing sequentialshooting, to arrange for the system control unit 70 to capture a stillimage with the monitoring regions 115 b, and to display this still imagethat has thus been captured upon the display panel 51. Furthermore itwould also be acceptable, when the photographic operation describedabove which consists of performing long timing photography is beingperformed, to arrange for the display control unit 71 to display thelive view image 152 captured by the monitoring regions 115 b upon thedisplay panel 51.

After the reset signals have been supplied to the first regions 115 aand the image capture operation has ended, it becomes possible to readout the charges in the first regions 115 a. Thus, the system controlunit 70 changes over from the state in which the live view image 152 isbeing captured to the state in which the live view image 151 is beingcaptured using both the first regions 115 a and also the monitoringregions 115 b (step S9). In this case, the system control unit 70repeatedly performs accumulation and reading out of charges at thepredetermined frame rate both for the first regions 115 a and also forthe monitoring regions 115 b. And the system control unit 70 displaysupon the display panel 51 the live view image 151 that has been capturedboth by the first regions 115 a and also by the monitoring regions 115 b(step S10).

After the live view image displayed upon the display panel 51 has beenchanged over, the system control unit 70 stores the image data for thestill image that has been generated by the image processing unit 30 withthe recording unit 60 (step S11). Due to this, the still image that hasbeen captured is recorded by the recording unit 60 as image data. Itshould be understood that it would also be acceptable to arrange for thesystem control unit 70 to display upon the display panel 51 a displayfor enabling the user to select whether or not the image processing unit30 should record or should delete the still image that has beencaptured. In this case it would be acceptable, if the user has selectedthat the still image is to be recorded, to arrange for the systemcontrol unit 70 to store the image data with the recording unit 60.Moreover it would be acceptable to arrange for the system control unit70 to delete the image data, if the user has selected that the stillimage is to be deleted.

As described above, according to this embodiment, since there areprovided the imaging unit 20 that is capable of performing image capturewith the first regions 115 a and with the monitoring regions 115 b, andthe system control unit 70 that is capable of employing differenttimings for reading out of the charges accumulated in the first regions115 a and for reading out of the charges accumulated in the monitoringregions 115 b, accordingly, even if it is not possible to performreading out of charges from one of the first regions 115 a and themonitoring regions 115 b, it is still possible to perform reading out ofcharges from the other thereof.

For example, even during an interval in which it is not possible to readout the charges from the first regions 115 a, it is still possible toperform reading out of charges from the monitoring regions 115 b. Due tothis, while for example capture of a still image is being performed bythe first regions 115 a, even during an interval in which the firstregions 115 a are being reset, the system control unit 70 is able toperform image capture of the live view image 152 by using only themonitoring regions 115 b, and to display this image upon the displaypanel 51. Accordingly, it is possible to cause the live view image 152to be displayed without interruption, even during capture of the stillimage. Due to this, it is possible to supply a digital camera 1 whoseconvenience of use is good.

A Second Example of Photographic Operation

FIG. 10 is a flow chart for explanation of another example ofphotographic operation performed by the system control unit 70 of thisfirst embodiment. In this example, a case will be described andexplained of operation in which a plurality of screens are set up on thedisplay panel 51, and a live view image is displayed upon each of thosescreens. First, when the power supply to the digital camera 1 is turnedon by the user and a predetermined actuation is performed upon theactuation unit 55 or the like in order to start photography, in asimilar manner to step S1 described above, the system control unit 70performs image capture operation with the imaging unit 20, and, alongwith capturing a live view image using both the first regions 115 a andalso the monitoring regions 115 b (step S21), also displays the liveview image that has thus been captured upon the display unit 51 (stepS22).

Next, the system control unit 70 makes a decision as to whether or notactuation of the preview switch 55 b by the user has been performed(step S23). If it is determined that actuation of the preview switch 55b has been performed (YES in step S23), then, as shown in FIG. 11(a),the system control unit 70 displays the live view image both in a mainscreen 51 a of the display panel 51 and also in a sub-screen 51 bthereof (step S24). In this case, the system control unit 70 displaysthe image 151A captured by the first regions 115 a of the image captureregion 114 (hereinafter this will be termed the “first image”) in themain screen 51 a. Moreover, the system control unit 70 (i.e. the displaycontrol unit 71) displays the image 152A captured by the monitoringregions 115 b of the image capture region 114 (hereinafter this will betermed the “second image”) in the sub-screen 51 b. In this manner, thedisplay control unit 71 displays the second image 152A as superimposedover the first image 151A that is displayed upon the display panel 51.The first image 151A and the second image 152A are both live view imagesthat have been captured of the same subject (faces of an animal 52 and52 a). It should be understood that, for example, it would also beacceptable for the second image 152A to be a captured image of a regionthat corresponds to a portion of the first image 151A (i.e. a partialimage). The first image 151A has a higher resolution, as compared tothat of the second image 152A.

Due to this, the user is able visually to compare the first image 151Athat is displayed in the main screen 51 a and the second image 152A thatis displayed in the sub-screen 51 b. For example, if the user changesthe image capture conditions (including the shutter speed, the gain, theframe rate, the white balance, the tone, and color compensation), thenoperation becomes possible to display a first image 151A in the mainscreen 51 a that has been captured under the image capture conditionsbefore change, and to display a second image 152A in the sub-screen 51 bthat reflects the image capture conditions after change. If this type ofactuation is to be performed, then first the system control unit 70determines whether or not the image capture conditions have been changedby the user (step S25). And, if it has been determined that the imagecapture conditions have been changed (YES in step S25), then the systemcontrol unit 70 captures the second image 152A with, for example, themonitoring regions 115 b under the image capture conditions afterchange, and displays this second image 152A in the sub-screen 51 b (stepS26). By looking at the first image 151A in the main screen 51 a andalso the second image 152A in the sub-screen 51 b, the user is able tocompare together images that have been captured before and after changeof the image capture conditions. Thereafter, the system control unit 70may set the image capture conditions after change for the first regions115 a.

It should be understood that, if it is determined that actuation of thepreview switch 55 b has not been performed (NO in step S25), then thesystem control unit 70 determines whether or not half press actuation ofthe release switch 55 a has been performed by the user (step S27). If itis determined that such half press actuation has been performed (YES instep S27), then the operations of step S29 that will be describedhereinafter and subsequent steps are performed. But if it is determinedthat such half press actuation has not been performed (NO in step S27),then the operations of step S25 and subsequent steps are repeated.

Next, the system control unit 70 determines with the image capturecontrol unit 72 whether or not half press actuation of the releaseswitch 55 a (i.e. actuation of SW1) has been performed by the user (stepS28). If it is determined that such half press actuation has beenperformed (YES in step S28), then the system control unit 70 performs AFoperation (step S29). This step S29 executes the same operation as thatof the step S4 shown in the flow chart of FIG. 8 . It should beunderstood that, if the system control unit 70 determines that such halfpress actuation of the release switch 55 a has not been performed (NO instep S28), then the flow of control returns to step S25 again, and theoperations of steps S25 through S28 are repeated.

After AF operation has been performed, the system unit 70 makes adecision with the image capture control unit 72 as to whether or notfull press actuation of the release switch 55 a (i.e. actuation of SW2)has been performed by the user (step S30). If it is determined that suchfull press actuation has been performed (YES in step S30), then thesystem control unit 70 performs image capture of the second image 152Awith the monitoring regions 115 b (step S31). And, as shown in FIG.11(b), along with deleting the display in the sub-screen 51 b, thesystem control unit 70 also displays this second image 152A in the mainscreen 51 a of the display panel 51 (step S32). It should be understoodthat, if it is determined that full press actuation has not beenperformed (NO in step S30), then the system control unit 70 returns backto the step S5, and repeatedly decides whether or not full pressactuation has been performed. At this time it would also be acceptable,if full press actuation is not performed during a predetermined timeperiod after the end of AF operation, to arrange for the system controlunit 70 to return the flow of control back to step S25, so as to performthe operation of steps S25 through S29 again.

Next, the system control unit 70 performs capture of a still image usingthe first regions 115 a (step S33). At this time, it would also beacceptable to arrange for the system control unit 70 to determine withthe image capture control unit 72 whether or not long timing photographyis being performed by the user, and for AF operation to be continuallyperformed if it is determined that long timing photography is beingperformed.

It should be understood that, while the image capture operationdescribed above is being performed, the system control unit 70continuously displays the second image 152A produced from the monitoringregions 115 b on the main screen 51 a. Accordingly, during the imagecapture operation, the system control unit 70 displays the second image152A captured by the monitoring regions 115 b upon the main screen 51 a.Furthermore it would also be acceptable, when long timing photography isbeing performed in the photographic operation described above, toarrange for the display control unit 71 to display the live view image152 that has been captured by the monitoring regions 115 b on the mainscreen 51 a.

After the still image capture operation has ended, the system controlunit 70 starts image capture of the first image 151A with the firstregions 115 a. And the system control unit 70 changes over from thestate in which the second image 152A is being displayed in the mainscreen 51 a as shown in FIG. 11(b) to the state in which the first image151A is being displayed in the main screen 51 a and the second image152A is being displayed in the sub-screen 51 b (step S34).

After changing over of the display has been performed, the systemcontrol unit 70 stores the image data for the still image that has beengenerated by the image processing unit 30 with the recording unit 60(step S35). Due to this, the still image that has been captured isstored by the recording unit 60.

In this manner, in this example, since it is arranged for the systemcontrol unit 70 to display the first image that is captured by the firstregions 115 a in the main screen 51 a of the display panel 51 and alsoto display the second image that is captured by the monitoring regions115 b in the sub-screen 51 b of the display panel 51, accordingly theuser is able to compare and observe together the first image in the mainscreen 51 a and the second image in the sub-screen 51 b. Moreover, sinceit is arranged for the system control unit 70 to capture two imagesunder mutually different image capture conditions, i.e. the imagecapture conditions for the first regions 115 a and the image captureconditions for the monitoring regions 115 b, and to display these twoimages that have thus been captured in the main screen 115 a and in thesub-screen 51 b which is superimposed thereupon, accordingly it ispossible to compare together two images in which the same subject iscaptured under mutually different image capture conditions. In this caseit becomes possible to compare together, for example, the depiction ofmovement due to shutter speed, the brightness, the white balance, andthe effects upon the image.

It should be understood that while, in this example, a case was citedand explained in which the system control unit 70 superimposed thesecond image 152A by displaying it in the single sub-screen 51 b, thisshould not be construed as being limitative. For example, it would alsobe acceptable to arrange for the system control unit 70 to superimposeseveral second images 152A upon the first image 151A by displaying themin two or more sub-screens 51 b. Moreover, while an example was citedand explained in which the system control unit 70 caused the secondimage 152A to be displayed in the sub-screen 51 b, this should not beconsidered as being limitative. For example it would also be acceptableto arrange for the system control unit 70, in step S22, to display inthe sub-screen 51 b a still image that has been stored. In this case,for example, it would be possible to arrange for the system control unit70 to display the newest still image in a single sub-screen 51 b, whileupdating it; or, alternatively, it would be possible to provide aplurality of sub-screens 51 b, and to arrange to display themsequentially in a row. Furthermore while, in this embodiment, an examplewas cited and explained in which a still image was captured, a similarexplanation would hold in a case in which a movie image was captured.Yet further, if a movie image is captured, then it would also beacceptable to arrange to obtain a still image by extracting a portion ofthe movie image.

The technical scope of the present invention is not to be considered asbeing limited to the embodiment described above; provided that the gistof the present invention is not departed from, various appropriatechanges and modifications may be added. For example while, in theembodiment described above, an example was cited in which the AFoperation was performed by a contrast detection method, this is not tobe construed as being limitative of the present invention; it would alsobe acceptable to arrange to perform the AF operation by a phasedifference detection method.

FIG. 12(a) is a figure for explanation of an example of the monitoringregions. As shown in FIG. 12(a), a first region 215 a and a monitoringregion 215 b are provided within each block region 215. The first region215 a has the same structure as the first region 115 a in the embodimentdescribed above. And the monitoring region 215 b includes a single redcolored pixel Pr, two green colored pixels Pg, and a single blue coloredpixel Pb. One of the two green colored pixels Pg1, Pg2 (for example, thegreen colored pixel Pg2) may be used as a focus detection pixel Pf.Moreover, the pixels in the monitoring region 215 b other than thisfocus detection pixel Pf, i.e. the red colored pixel Pr, the other greencolored pixel Pg, and the blue colored pixel Pb, may be used for captureof a live view image or the like.

The focus detection pixel Pf is used for detecting the focal point ofthe image capture optical system 11. Two photodiodes (PD104 a, 104 b)are provided to this focus detection pixel Pf. The PDs 104 a and 104 bmay, for example, be arranged along the X direction, and reading out oftheir charges can be performed independently. A focus detection pixel Pfof this type is provided in each of the monitoring regions 215 b.Moreover, for example, separator lenses (not shown in the figures) maybe provided and may form images upon the two PDs 104 a, 104 b of thephotographic subject that have passed through the image capture system11.

With this structure, the amount of focus deviation is detected byobtaining the gap between the two images of the photographic subjectthat have passed through the image capture optical system 11 and havebeen created separately upon the two PDs 104 a, 104 b by the separatorlenses. For example, in the focus adjusted state (i.e. the focusedstate), the gap between the two images is equal to a predeterminedvalue. Furthermore, if the surface upon which the focus is adjusted ismore toward the side of the focus detection pixels Pf than the imagingplane, then the gap between the two images is smaller than thepredetermined value. Moreover, if the surface upon which the focus isadjusted is more toward the side of the image capture optical system 11than the imaging plane, then the gap between the two images is greaterthan the predetermined value. Accordingly, the system control unit 70 isable to adjust the focus of the image capture optical system 11 byshifting the focusing lens 11 c so that the gap between the two imagesdetected by the PDs 104 a, 104 b of the focus detection pixel Pf becomesequal to the predetermined value.

It should be understood that the focus detection pixels Pf are notlimited to being employed for detection of the focus of the imagecapture optical system 11; for example, it would also be possible toemploy them for image capture, in a similar manner to the other pixelsP. In this case, it would be possible for the system control unit 70 tochange over the pixels Pf for focus detection either to being used forfocus detection or to being used for image capture, as appropriate. Forexample, when AF operation according to a phase difference detectionmethod is being performed, then the pixels Pf for focus detection may beused for focus detection, whereas, when AF operation according to thephase difference detection method is not being performed, then thepixels Pf for focus detection may be changed over to being used forimage capture.

Moreover while, in the embodiment described above, an example has beencited and explained in which first regions 115 a and monitoring regions115 b are provided to each of the block regions 115, this is not to beconsidered as being limitative. FIG. 12(b) is a figure showing anotherexample of one of the block regions 315. As shown in this FIG. 12(b), itis also possible to provide a structure in which a first region 315 a, asecond region 315 b, and a monitoring region 315 c are provided to eachof the block regions 315.

With the structure shown in FIG. 12(b), it is possible to read out thecharges from the first region 315 a, from the second region 315 b, andfrom the monitoring region 315 c at mutually different timings.Moreover, the image capture control unit 72 of the system control unit70 (refer to FIG. 7 ) is capable of setting different image captureconditions individually for each of the first region 315 a, the secondregion 315 b, and the monitoring region 315 c.

According to this structure, by receiving the light flux from thephotographic subject upon the first regions 315 a and the second regions315 b, and by performing image capture under mutually differentconditions for the first regions 315 a and the second regions 315 b, itis possible to perform image capture with a single block region 315according to a plurality of different image capture conditions, so thatit is possible to perform photometry at high accuracy. Due to this, itbecomes possible to capture an image over a broad dynamic range.Furthermore, since it is possible to perform image capture according toimage capture conditions in which the evaluated value of the contrast ofthe image of the photographic subject becomes higher, accordingly, in acase in which AF processing is performed according to a contrastdetection method, the accuracy of adjustment of the focusing position isenhanced.

Moreover, for example, while in the example described above it wasarranged for the system control unit 70 to perform AF processing on thebasis of the fact that half press actuation of the release switch 55 ahad been performed, this should not be construed as being limitative.For example, it would be acceptable to arrange for the system controlunit 70 to perform AF processing during photography of a live view imageand also during photography of a movie image.

Furthermore while, in the embodiment described above, an example wascited and explained in which the plurality of monitoring regions 115 bwere of mutually equal dimensions and shapes, this is not to beconstrued as being limitative; it would also be acceptable for thedimensions or the shape of at least a single one of the monitoringregions 115 b to be different. Moreover, while an example was cited andexplained in which the monitoring regions 115 b were arranged regularlyand systematically, this is not to be construed as being limitative; itwould also be acceptable for the monitoring regions 115 b to be arrangedirregularly.

Yet further while, with the structure described above, the monitoringregions 115 b were made up of red colored pixels Pr, green coloredpixels Pg, and blue colored pixels Pb, this is not to be considered asbeing limitative; it will be sufficient for each of the monitoringregions 115 b to include one or more pixels of at least one type, i.e.red colored pixels Pr, green colored pixels Pg, and blue colored pixelsPb.

Even further, in the structure described above, it would also beacceptable to arrange for the image processing unit 30 to generate animage by supplementing the portions among the first regions 115 acorresponding to the monitoring regions 115 b on the basis of the pixelsignals from regions surrounding the monitoring regions 115 b. By doingthis, it would be possible to prevent reduction of the quality of theimage captured by the first regions 115 a, since it would be possible tosuppress the loss of the pixels in the first regions 115 a due to theprovision of the monitoring regions 115 b.

Still further while, in the embodiment described above, an example wascited and explained of a case in which the system control unit 70displayed upon the display panel 51 a live view image captured by themonitoring regions 115 b when full press actuation of the release switch55 a was performed, this is not to be construed as being limitative. Forexample, it would also be acceptable to arrange to display the live viewimage from the monitoring regions 115 b upon the display panel 51 whenhalf press actuation of the release switch 55 a has been performed.

Embodiment #2

Explanation of a Laminated Type Imaging Element

First, a laminated type imaging element 100 will be explained that ismounted to an electronic device (for example, to an imaging device 1)according to a second embodiment of the present invention. It should beunderstood that this laminated type imaging element 100 is one describedin Patent Application 2012-139026 previously filed by the applicant ofthe present application. FIG. 13 is a sectional view of this laminatedtype imaging element 100. The imaging element 100 comprises abackside-illumination type image capture chip 113 that outputs pixelsignals corresponding to incident light, a signal processing chip 111that processes the pixel signals, and a memory chip 112 that stores thepixel signals. The image capture chip 113, the signal processing chip111 and the memory chip 112 are laminated together, and are mutuallyelectrically connected together by electrically conductive bumps madefrom Cu or the like.

It should be understood that, as shown in the figure, incident light isprincipally incident towards the +Z axis direction shown by the outlinedwhite arrow sign. In this embodiment, the surface of the image capturechip 113 upon which the incident light is incident is termed its “rearsurface”. Moreover, as shown by the coordinate axes, the leftwarddirection on the drawing paper orthogonal to the Z axis is taken asbeing the +X axis direction, while the direction perpendicular to the Zaxis and the X axis towards the viewer is taken as being the +Y axisdirection. In some of the following figures the coordinate axes of FIG.13 are employed as reference, and are shown so that the orientations ofthose figures can be determined.

The example of an image capture chip 113 in this example is an MOS imagesensor of the backside-illumination type. A PD layer 106 is disposed onthe rear surface of a wiring layer 108. This PD layer 106 comprises aplurality of PDs (i.e. photo-diodes)104 that are arranged in atwo-dimensional array and that accumulate electric change according toincident light, and transistors 105 that are provided to correspond tothese PDs 104.

Color filters 102 are provided upon the light-incident side of the PDlayer 106 with a passivation layer 103 interposed between them. Thesecolor filters 102 are of a plurality of types that pass mutuallydifferent wavelength bands, and are disposed in a specific arrangementthat corresponds to the arrangement of the PDs 104. The arrangement ofthe color filters 102 will be explained hereinafter. Each group thatincludes one of the color filters 102, one of the PDs 104, and one ofthe transistors 105 constitutes one pixel.

Micro-lenses 101 are provided upon the sides of the color filters 102upon which light is incident, and correspond to the abovementionedpixels. These micro-lenses 101 condense the incident light upon theircorresponding PDs 104.

The wiring layer 108 includes wiring 107 that transmits the pixelsignals from the PD layer 106 to the signal processing chip 111. Thiswiring 107 may be multi-layered, and also could be provided with passiveelements and active elements.

A plurality of bumps 109 are disposed upon the front surface of thewiring layer 108. This plurality of bumps 109 are positionally alignedwith a plurality of bumps 109 that are provided on the opposing face ofthe signal processing chip 111, and these mutually positionally alignedbumps 109 are joined together and are electrically connected together bythe image capture chip 113 and the signal processing chip 111 beingpressurized together, or the like.

In a similar manner, the plurality of bumps 109 and are disposed uponthe mutually opposing faces of the signal processing chip 111 and of thememory chip 112. These bumps 109 are mutually positionally aligned, andthe mutually aligned bumps 109 are joined together and are electricallyconnected together by the signal processing chip 111 and the memory chip112 being pressurized together, or the like.

It should be understood that the joining between the bumps 109 is notlimited to being Cu bump joining by solid phase diffusion; it would alsobe acceptable to arrange to employ micro-bump connection by soldermelting. Furthermore, for example, it would also be possible to provideat least one set of bumps 109 for a single unit region that will bedescribed hereinafter. Accordingly, it would be acceptable for the sizesof the bumps 109 to be set to be larger than the pitch of the PDs 104.Moreover it would also be possible, in peripheral regions other than thepixel region in which pixels are disposed, to provide larger bumps thanthe bumps 109 that correspond to the pixel region.

The signal processing chip 111 has a TSV 110 (through silicon electrode)that mutually connects together circuitry provided upon its frontsurface and upon its rear surface respectively. This TSV 110 isdesirably provided at a peripheral region. Moreover, such a TSV 110 mayalso be provided at a peripheral region of the image capture chip 113and/or at the memory chip 112.

FIG. 14 is a figure for explanation of the arrangement of pixels on theimage capture chip 113, and for explanation of unit groups 131 of thosepixels. In particular, this figure shows a situation in which the imagecapture chip 113 is viewed from its rear surface side. For example,20,000,000 or more pixels may be arranged in this image capture region114 in a matrix configuration. In this embodiment, for example, a singleblock 131 may be constituted by 64 adjacent pixels in an 8B8arrangement. The lattice lines in the figure show the concept ofgrouping together adjacent pixels and thereby defining the blocks 131.The number of pixels that make up each of the blocks 131 is not to beconsidered as being particularly limited; for example, a block could be32 pixels B 64 pixels, or larger or smaller. In this embodiment, nocircuit or wiring or the like is provided between the plurality ofblocks 131, so that the plurality of blocks can be arranged closelytogether, and thereby a reduction of the space occupied is implemented.

As shown in the partial enlarged view of the pixel region, a block 131includes 16 so-called Bayer arrays arranged vertically and horizontally,each formed by four pixels, i.e. two green colored pixels Gb and Gr, ablue colored pixel B, and a red colored pixel R. The green coloredpixels are pixels having green colored filters as their color filters102, and thus receive light of the green colored wavelength band in theincident light. In a similar manner, the blue colored pixels are pixelshaving blue colored filters as their color filters 102, and thus receivelight of the blue colored wavelength band in the incident light, and thered colored pixels are pixels having red colored filters as their colorfilters 102, and thus receive light of the red colored wavelength bandin the incident light.

In this embodiment, a plurality of the blocks 131 are defined so that atleast one group of two green colored pixels Gb and Gr, a blue coloredpixel B and a red colored pixel R is included in one block 131, and, ineach of these blocks 131, the pixels included in the blocks 131 can becontrolled with mutually different control parameters. In other words,it is possible to acquire image capture signals from pixel groupsincluded in some block 131 and from pixel groups included in anotherblock 131, for which the image capture conditions are mutuallydifferent. Examples of control parameters are: the frame rate, the gain,the sub-sampling ratio, the number of rows or columns of pixel signalsto be added together, the time interval for charge accumulation or thenumber of times of charge accumulation, the number of bits fordigitization, and so on. Furthermore, such control parameters could alsobe parameters for the image processing that is performed afteracquisition of image signals from the pixels.

FIG. 15 is a circuit diagram corresponding to one block 131 of the imagecapture chip 113. In FIG. 15 , the representative rectangle surroundedby a dotted line indicates a circuit that corresponds to a single pixel.In the example of FIG. 15 , 16 pixels among the 64 pixels thatconstitute the block 131 are shown by way of example. It should beunderstood that, in the following explanation, at least some of thetransistors correspond to the transistors 105 of FIG. 1 .

Each of the PDs 104 for these pixels is connected to a correspondingtransfer transistor 302, and TX wiring 307 (a transfer section controlline) to which transfer pulses are supplied is connected to the gates ofthese transfer transistors 302. In this embodiment, the TX wiring 307 isconnected to all of the 64 transfer transistors 302 in common.

The drain of each of the transfer transistors 302 is connected to thesource of a corresponding reset transistor 303, and a so-called floatingdiffusion FD is defined between the drain of each of the transfertransistors 302 and the source of the corresponding reset transistor303, and is connected to the gate of an amplification transistor 304.The drain of each of the reset transistors 303 is connected to Vddwiring 310 to which power supply voltage is supplied, and its gate isconnected to reset wiring 306, with reset pulses being supplied to thisgate. In this embodiment, the reset wiring 306 is connected to all ofthe 64 reset transistors 303 in common.

The drain of each of the amplification transistors 304 is connected tothe Vdd wiring 310 to which the power supply voltage is supplied.Moreover, the source of each of the amplification transistors 304 isconnected to the drain of the corresponding one of the selectiontransistors 305. The gate of each of the selection transistors 305 isconnected to decoder wiring 308 to which selection pulses are supplied.In this embodiment, the decoder wiring 308 is provided to each of the 64selection transistors 305 independently. The sources of the selectiontransistors 305 are connected to output wiring 309 in common. A loadcurrent source 311 supplies current to the output wiring 309. In otherwords, the output wiring 309 for the selection transistors 305 isconstituted as a source follower. It should be understood that this loadcurrent source 311 could also be provided on the side of the imagecapture chip 113, or on the side of the signal processing chip 111.

Now, the flow of operation from the start of charge accumulation untilpixel output after accumulation has ended will be explained. A resetpulse is supplied to the reset transistor 303 via the reset wiring 306,and, simultaneously therewith, a transfer pulse is supplied to thetransfer transistor 302 via the TX wiring 307, so that the potentials ofthe PD 104 and of the floating diffusion FD are reset.

When supply of the transfer pulse to the PD 104 is cancelled, theincident light is converted to electrical charge and is accumulated.And, when subsequently a transfer pulse is supplied for a second time inthe state in which no reset pulse is being supplied, the charge that hasbeen accumulated is transferred to the floating diffusion FD, and thepotential of the floating diffusion FD changes from the reset potentialto the signal potential after charge accumulation. And, when a selectionpulse is supplied to the selection transistor 305 via the decoder wiring308, change of the signal potential of the floating diffusion FD istransmitted to the output wiring 309 via the amplification transistor304 and the selection transistor 305. Due to this, a pixel signalcorresponding to the reset potential and to the signal potential isoutput from this unit pixel to the output wiring 309.

As shown in FIG. 15 , in this embodiment, the reset wiring 306 and theTX wiring 307 are provided in common for the 64 pixels that make up theblock 131. In other words, the reset pulse and the transfer pulse areapplied simultaneously to all of these 64 pixels. Accordingly, all ofthe pixels that make up the block 131 start accumulation of charge atthe same timing and stop accumulation of charge at the same timing.However, due to the fact that the selection pulses are appliedsequentially to each of the selection transistors 305, the pixel signalscorresponding to the charges that have been accumulated are selectivelyoutput to the output wiring 309 for each pixel P. Moreover, the resetwiring 306, the TX wiring 307, and the output wiring 309 are providedseparately for each of the blocks 131.

It is possible to control the charge accumulation interval for each ofthe blocks 131 by building the circuit while taking the blocks 131 asreference in this manner. To put this in another way, for different onesof the blocks 131, it is possible to output pixel signals basedaccording to frame rates that are mutually different. Furthermore, whilecharge accumulation is being performed one time for one of the blocks131, by repeating charge accumulation for another of the blocks 131 anyappropriate number of times and by outputting pixel signals each time,it is possible to output frames for movie use at frame rates that aredifferent between these blocks 131.

FIG. 16 is a block diagram showing the functional structure of theimaging element 100. An analog multiplexer 411 selects the 64 PDs 104that make up the block 131 in order, and outputs their respective pixelsignals to the output wiring 309 that is provided to correspond to thatblock 131. The multiplexer 411 is formed upon the image capture chip 113along with the PDs 104.

The pixel signals output via the multiplexer 411 are subjected tocorrelated double sampling (CDS) and analog/digital (A/D) conversion bya signal processing circuit 412 that is formed upon the signalprocessing chip 111, and thereby are subjected to CDS and A/Dconversion. After the above described A/D conversion, the pixel signalsare input to adders 416 that correspond respectively to each of thepixels. The adders 416, which respectively correspond to the pixels, addtogether the pixel signals outputted from the demultiplexer 413 andpixel signals that are read out from pixel memories 414, and output thepixels signals after addition back to the pixel memories 414 for asecond time.

The pixel memories 414 store the pixel signals from the adders 416. Eachof the pixel memories 414 has a capacity that is capable of storing thepixel signals after addition. The demultiplexer 413, the adders 416, andthe pixel memories 414 are formed upon the memory chip 112.

FIG. 17 is a figure for explanation of the flow of the pixel signal forone pixel. In FIG. 17 , the pixel signal S that is output from thedemultiplexer 413 is input to an adder n, which corresponds to one ofthe adders 416. At this time, the pixel signal P that is stored in thecorresponding memory n, which corresponds to one of the pixel memories414, is read out from that memory n and is also inputted to the adder n.

The adder n adds together the pixel signal S and the pixel signal P thatare input, and outputs the pixel signal S+P after addition to the pixelmemory n. And the pixel memory n stores this pixel signal S+P that hasbeen input, and waits for it to be read out to the calculation circuit415. Here, when addition is performed by the adder n, it is possible tooutput only the pixel signal S that has been input to the adder n justas it is from the adder n to the pixel memory n, by controlling thepixel memory 414 so that the pixel signal P that is being stored in thepixel memory n is not read out. In other words, it is also possible foraddition not to be performed by the adder n, and for the pixel signal Sfrom the image capture chip 113 to be read out to the calculationcircuit 415 from the memory n just as it is.

The calculation circuit 415 processes the pixel signal stored in thepixel memory 414 and transfers it to a subsequent stage image processingunit. The calculation circuit 415 may be provided upon the signalprocessing chip 111, or may be provided upon the memory chip 112.

A drive control unit 417 generates timing control signals forsynchronizing the timings at which the pixel signals are sent from theimage capture chip 113 to the signal processing chip 111 and to thememory chip 112, the timings at which the pixel signals in the pixelmemories 414 are read out and are stored therein, the pixel signaladdition timings for the adders 416, and the timings at which the pixelsignals are transferred to the calculation circuit 415.

It should be understood that while, in FIG. 16 , the connections for asingle one of the blocks 131 are shown, actually these connections arepresent for each of the blocks 131, and operate in parallel. However, itis not necessary for a calculation circuit 415 to be provided for eachof the blocks 131; for example, it would also be acceptable to arrangefor processing to be performed sequentially while a single calculationcircuit 415 refers in order to the values in the pixel memories 414corresponding to each of the blocks 131.

As described above, output wiring 309 is provided to correspond to eachof the blocks 131. Since, in this imaging element 100, the image capturechip 113, the signal processing chip 111, and the memory chip 112 arelaminated together, accordingly, by using electrical connections betweenthese chips that employ the bumps 109 in the output wiring 309, it ispossible to extend the wiring without making the chips larger in theirplanar direction.

Explanation of the Imaging Device

FIG. 18 is a block diagram showing an example of the structure of animaging device 1 that includes the imaging element 100 described above.In FIG. 18 , the imaging device 1 comprises an image capture opticalsystem 10, an imaging unit 20, an image processing unit 30, a workingmemory 40, a display unit 50, a recording unit 60, and a control unit70.

The image capture optical system 10 consists of a plurality of lenses,and conducts a light flux from the photographic field to the imagingunit 20. This image capture optical system 10 may be built integrallywith the imaging device 1, or may be built so as to be detachable fromthe imaging device 1. Moreover, it would also be acceptable to house afocus lens within the image capture optical system 10, or to house azoom lens therein.

The imaging unit 20 comprises the imaging element 100 mentioned aboveand a drive unit 21 that drives the imaging element 100. By the imagingelement 100 being drive controlled by control signals output by thedrive unit 21, control can be executed for charge accumulation to beperformed by each of the blocks 131 described above. Command of thedrive unit 21 for control of charge accumulation is performed by thecontrol unit 70.

In cooperation with the working memory 40, the image processing unit 30performs image processing upon image data captured by the imaging unit20. In this embodiment, apart from temporarily storing image data and soon before and after JPEG compression and/or before and after MPEGcompression, the working memory 40 is also used as a buffer memory forimages captured by the imaging unit 20. The display unit 50 may include,for example, a liquid crystal display panel 51, and displays images(still images and movie images) captured by the imaging unit 20 andinformation of various kinds, as well as displaying a screen foroperational input. In the structure of this display unit 50, a touchpanel 52 is laminated over the display surface of the liquid crystaldisplay panel 51. The touch panel 52 outputs a signal specifying theposition at which the user has touched the liquid crystal display panel51.

The recording unit 60 stores data of various types upon a storage mediumsuch as a memory card or the like, such as image data acquired inresponse to an image capture command (i.e. in response to releaseactuation that will be described hereinafter) and so on. And the controlunit 70 includes a CPU, and controls the overall operation of theimaging device 1. For each block 131 of the imaging element 100 (i.e. ofthe image capture chip 113), the control unit 70 issues commands forvarious control parameters to the drive unit 21 so as to causes an imageto be acquired at a predetermined frame rate (i.e., with a predeterminedcharge accumulation time interval) and at a predetermined gain, andreading out control of the acquired image data to be performed.

Moreover, on the basis of the image data, the control unit 70 performswhite balance adjustment with an AWB calculation unit 71. Andfurthermore, the control unit 70 generates an image for replay displayon the basis of the pixel signals, and displays this image upon thedisplay unit 50.

The Monitoring Sensor

In this embodiment, the charge accumulation time interval for all of thepixels included in each of these blocks 131 is determined on the basisof the charge accumulation amount measured by a monitoring sensor. Here,the sensor that determines the charge accumulation amount of the pixelsis termed a “monitoring sensor”. FIG. 19 is a figure for explanation ofthe arrangement of the plurality of pixels in one of the blocks 131. Inthis imaging device 1, a single green colored pixel Gr(3,4) that ispositioned at the approximate center of the block 131 is made tofunction as a monitoring sensor that is representative of this block131.

During photography of, for example, a still image, the control unit 70sends commands to the drive unit 21 for reading out pixel signals fromeach of the blocks 131 of the imaging element 100 (i.e. of the imagecapture chip 113) at predetermined time intervals that are determined inadvance. For example, the pixel signals are read out at a plurality ofseparated time points t1, t2, t3, . . . t7, t8.

And, among the pixel signals that have thus been read out, the controlunit 70 checks the pixel signal levels from the monitoring sensors (i.e.from the green colored pixels Gr(3,4)). Moreover, at the time point (forexample, the time point t5) that the integrated value of the pixelsignals that have been read out has exceeded a decision threshold valuethat is determined in advance, the time interval until the time pointone before that time point (i.e. until the time point t4) is determinedas being the charge accumulation time interval for all of the pixels inthe corresponding block 131. In this case, the reading out of the pixelsignals from this block 131 after the time point t6 is cancelled.

FIG. 20 is a figure showing, for the block 131, the relationship betweenall the pixel positions and their pixel signal levels. If the pixelsignal level from the monitoring sensor (i.e. the green colored pixelGr(3,4)) exceeds the decision threshold value, then the control unit 70stops the accumulation of charge for all of the pixels within this block131, even if the pixel signal levels from other pixels are smaller thanthe decision threshold value. Conversely, if the pixel signal level fromthe monitoring sensor (i.e. the green colored pixel Gr(3,4)) has notexceeded the decision threshold value, then the control unit 70continues the accumulation of charge for all of the pixels within thisblock 131, even if the pixel signal levels from other pixels are greaterthan the decision threshold value.

However, the control unit 70 takes the time period until the time pointt8 as being the upper limit for the charge accumulation time interval,even if at this time point t8 the pixel signal level from the monitoringsensor (i.e. the green colored pixel Gr(3,4)) that is read out has notexceeded the decision threshold value described above.

An Example of Reading Out the Pixel Signals

The reading out of the pixel signals from a block 131 will now beexplained with reference to FIG. 21 , which explains the timings forreading out the pixel signals, the charge accumulation time interval ofthe image capture chip 113, and the pixel signals that are read out fromthe imaging element 100 via the calculation circuit 415.

The drive unit 21 controls the imaging element 100 in the followingmanner. That is, the first charge accumulation time interval is taken asbeing from the time point t0 at which accumulation is started until thetime point t1, and the second charge accumulation time interval is takenas being from the time point t0 until the time point t2. The drive unit21 starts charge accumulation for the pixels included in the block 131at the time point to. And, at the time point t1, the pixel signals fromthe block 131 are output while controlling the pixel memories 414 sothat the pixel signal which is stored in the pixel memory n, in theexample shown in FIG. 17 , is not read out. Due to this, the pixelsignal a accumulated during the first charge accumulation time interval(from the time point t0 to the time point t1) is output from thedemultiplexer 413, and is output via the calculation circuit just as itis as a signal A. This pixel signal A (=a) is also stored in the pixelmemory n.

When performing the reading out of the pixel signal described above atthe time point t1, the drive unit 21 also immediately starts chargeaccumulation by the pixels included in the block 131. And the pixelsignals from the block 131 are output at the time point t2, whilecontrolling the pixel memories 414 so as to read out the pixel signal astored in the pixel memory n shown by way of example in FIG. 17 . Due tothis, the pixel signal b accumulated from the time point t1 until thetime point t2 is output from the demultiplexer 413, and this pixelsignal b and the pixel signal a read out from the pixel memory n areadded together by the adder n. The pixel signal a+b after addition isoutput via the calculation circuit 415 as a signal B. This pixel signalB is stored in the pixel memory n. Since the pixel signal B (=a+b) isthe sum of the pixel signals accumulated from the time point t0 to thetime point t1, and from the time point t1 to the time point t2,accordingly it is equivalent to the pixel signal accumulated during thesecond charge accumulation time interval (i.e. from the time point t0 tothe time point t2).

In a similar manner, when performing the reading out of the pixel signaldescribed above at the time point t2, the drive unit 21 also immediatelystarts charge accumulation by the pixels included in the block 131. Andthe pixel signals from the block 131 are output at the time point t3,while controlling the pixel memories 414 so as to read out the pixelsignal B stored in the pixel memory n shown by way of example in FIG. 17. Due to this, the pixel signal c accumulated from the time point t2until the time point t3 is output from the demultiplexer 413, and thispixel signal c and the pixel signal B read out from the pixel memory nare added together by the adder n. The pixel signal B+c after additionis output via the calculation circuit 415 as a signal C. This pixelsignal C is also stored in the pixel memory n. Since the pixel signal C(=B+c) is the sum of the pixel signals accumulated from the time pointt0 to the time point t2, and from the time point t2 to the time pointt3, accordingly it is equivalent to the pixel signal accumulated duringthe third charge accumulation time interval (i.e. from the time point t0to the time point t3).

Subsequently, in a similar manner, by reading out the pixel signals fromthe time point t4 to the time point t8, it is possible to obtain thepixel signals accumulated during each of the fourth charge accumulationtime interval (from the time point t0 to the time point t4), the fifthcharge accumulation time interval (from the time point t0 to the timepoint t5), the sixth charge accumulation time interval (from the timepoint t0 to the time point t6), the seventh charge accumulation timeinterval (from the time point t0 to the time point t7), and the eighthcharge accumulation time interval (from the time point t0 to the timepoint t8). It should be understood that, as described above, theaccumulation of charge up to the eighth charge accumulation timeinterval only takes place if the integrated value of the pixel signalfrom the monitoring sensor (i.e. the green colored pixel Gr(3,4)) doesnot exceed the decision threshold value which has been determined inadvance.

The Normalization Processing

As explained above, if the amount of incident light is different betweendifferent ones of the blocks 131 when determining the chargeaccumulation time interval for each of the blocks 131, then in somecases the charge accumulation time intervals differ between the variousblocks 131. Due to this, the control unit 70 creates an image byperforming normalization processing related to the charge accumulationtime intervals between the blocks 131.

FIG. 22 is a figure for explaining this normalization processing. Forexample, if the pixel signal values of the block 131, when the chargeaccumulation time interval is the eighth charge accumulation timeinterval (from the time point t0 to the time point t8), are taken as areference, then, for a block 131 for which the charge accumulation timeinterval is the second charge accumulation time interval (from the timepoint t0 to the time point t2), the pixel signal values are calculatedby being quadrupled (=8/2). Moreover, for a block 131 for which thecharge accumulation time interval is the fourth charge accumulation timeinterval (from the time point t0 to the time point t4), the pixel signalvalues are calculated by being doubled (=8/4). And, for a block 131 forwhich the charge accumulation time interval is the fifth chargeaccumulation time interval (from the time point t0 to the time pointt5), the pixel signal values are calculated by being multiplied by 8/5.The same holds for the other charge accumulation time intervals.

The control unit 70 normalizes the pixel signal values to apredetermined bit length (for example, 14 bits) after having adjustedthe pixel signal values according to the differences between the chargeaccumulation time intervals for the various blocks, as described above.Due to this, an image is obtained having a wide dynamic range, in whichthe magnitudes of the signal values originating in discrepancies in thecharge accumulation time interval between the different blocks 131 havebeen corrected. The control unit 70 performs white balance adjustmentwith the AWB calculation unit 71 on the basis of the pixel signals afternormalization processing has been performed in this manner.

Explanation of the Flow Chart

FIG. 23 is a flow chart for explanation of the flow of photographicoperation performed by the control unit 70 of the imaging device 1. Whenan on-off switch not shown in the figures is actuated to turn the powersupply on, power is supplied to the various sections of the imagingdevice 1, and repetition of the processing in FIG. 23 is started. And,even if a release button not shown in the figures has been half pressactuated, the control unit starts the processing in FIG. 23 . Half pressactuation is an actuation mode in which the release button is presseddownward to a shallower extent than during full press actuation.

In step S101 of FIG. 23 , the control unit 70 makes a decision as towhether or not release actuation (in other words, full press actuationof the release button) has been performed. If an actuation signal thatspecifies that the release button has been full press actuated is input,then the control unit 70 reaches an affirmative decision in step S101,and the flow of control proceeds to step S102. On the other hand, if thefull press actuation described above has not been performed, then thecontrol unit 70 reaches a negative decision in step S101, and the abovedecision processing is repeated.

In step S102, the control unit 70 sends a command to the drive unit 21and starts accumulation of charge for all of the blocks 131 of theimaging element 100, and then the flow of control proceeds to step S103(this corresponds to the time point t0 described above). In step S103,the pixel signals are read out from the image capture chip 113 in unitsof the blocks 131. Then in step S104 the adders 416 add together thepixel signals that have been read out corresponding to each of thepixels and the pixel signals that are stored in the pixel memories 414.The pixel signals after addition are then again stored in the pixelmemories 414.

In step S105, for each of the blocks 131, in relation to the pixelsignals from the monitoring sensors, the control unit 70 makes adecision as to whether or not the integrated value after addition hasexceeded the decision threshold value that has been set in advance. And,for those blocks 131 for which the decision threshold value has beenexceeded, the control unit 70 reaches an affirmative decision in thisstep S105, and the flow of control proceeds to step S106. However, forthose blocks 131 for which the decision threshold value has not beenexceeded, the control unit 70 reaches a negative decision in this stepS105, and the flow of control returns to step S103. If the flow ofcontrol returns to step S103, then the processing described above forthat block 131 is continued.

In step S106, the control unit 70 sends a command to the drive unit 21to terminate charge accumulation for the corresponding block 131 that isthe current subject, and then the flow of control proceeds to step S107.In step S107, the control unit 70 performs normalization processing inrelation to the charge accumulation charge intervals between the blocks131, as described above, and then the flow of control proceeds to stepS108.

In step S108, the control unit 70 sends a command to the AWB calculationunit 71 and performs white balance processing, and then the flow ofcontrol proceeds to step S109. In step S109, the control unit 70 sends acommand to the recording unit 60 and records the image data upon astorage medium such as a memory card or the like, and then theprocessing of FIG. 23 terminates.

According to this second embodiment as explained above, the followingbeneficial operational effects are obtained.

(1) It is arranged for the imaging device 1 to comprise: the imagecapture chip 113 upon which the plurality of PDs 104 are arranged; thecontrol unit 70 that subdivides the image capture chip 113 into aplurality of area blocks 131 each of which includes a plurality of PDs104, that controls the charge accumulation time intervals of the PDs 104by units of area blocks 131, and that moreover is capable of reading outthe accumulated signals by units of area blocks 131; and at least afirst monitoring sensor Gr(3,4) and a second monitoring sensor Gr(3,4)that are respectively provided to a first area block 131 and a secondarea block 131, and that are capable of reading out charge accumulationamounts from their corresponding PDs 104. Due to this, it is possible toobtain an appropriate exposure for each area of the image correspondingto each block 131. For example, even in the case of backlit photography,without saturating the background, it is possible to obtain an adequateexposure also for the main photographic subject. Moreover it isunnecessary to redo photographic operation, since it is possible toobtain an appropriate exposure with one photographic shot.

(2) While the plurality of PDs 104 include some PDs 104 upon which colorfilters 102 of green color Gr (Gb) are provided and some PDs 104 uponwhich color filters 102 of other colors (i.e. B and R) than green colorGr (Gb) are provided, the first monitoring sensor Gr(3,4) and the secondmonitoring sensor Gr(3,4) are constituted by PDs 104 upon which colorfilters 102 of green color Gr (Gb) are provided in the first area block131 and the second area block 131. By using as the monitoring sensorsPDs 104 upon which color filters 102 of green color are provided whosesensitivity is generally high, it is possible to obtain appropriatecharge accumulation amounts.

(3) Since it is arranged to provide the first monitoring sensor Gr(3,4)and the second monitoring sensor Gr(3,4) at the approximate centers ofthe first area block 131 and the second area block 131, accordingly itis possible to obtain charge accumulation amounts that are based uponrepresentative amounts of incident light for each of these blocks 131.

(4) Since, when the amount of charge accumulated by the first monitoringsensor Gr(3,4) reaches the predetermined charge accumulation amount, thecontrol unit 70 stops charge accumulation by the PDs 104 included in thecorresponding first area block 131, accordingly it is possible tocontrol the charge accumulation time interval by the PDs 104 of thisfirst area block 131 in an appropriate manner.

(5) Moreover since, when the amount of charge accumulated by the secondmonitoring sensor Gr(3,4) reaches the predetermined charge accumulationamount, the control unit 70 stops charge accumulation by the PDs 104included in the corresponding second area block 131, accordingly it ispossible to control the charge accumulation time interval by the PDs 104of this second area block 131 in an appropriate manner.

(6) Since the control unit 70 reads out the accumulated signals from thePDs 104 that have ended accumulation of charge by units of area blocks131, accordingly it is possible to read out the pixel signals for eacharea of the image in an appropriate manner corresponding to each block131.

(7) And, since the control unit 70 starts reading out of the chargeaccumulation amounts from the first monitoring sensor Gr(3,4) and fromthe second monitoring sensor Gr(3,4) according to release actuation,accordingly it is possible to detect the charge accumulation amounts inan appropriate manner after release actuation (in other words, after acommand for photography has been issued).

(8) In this imaging element 100, the plurality of PDs 104 are arrayed inthe image capture chip 113, and it is arranged: for it to be possible tocontrol the charge accumulation time intervals of the PDs 104 by aplurality of area block units 131 into which the image capture chip 113is subdivided so that a plurality of the PDs 104 are included therein;for it to be possible to read out the signals accumulated in the PDs 104by the area block units 131; to provide at least a first monitoringsensor Gr(3,4) and a second monitoring sensor Gr(3,4) to a first areablock 131 and to a second area block 131 respectively; and for it to bepossible to read out charge accumulation amounts obtained by the PDs inthe first area block 131 and charge accumulation amounts obtained by thePDs 131 in the second area block 131 from the first monitoring sensorGr(3,4) and from the second monitoring sensor Gr(3,4), respectively. Byemploying this type of imaging element 100, it is possible to obtain anappropriate exposure for each area of the image corresponding to eachblock 131. For example, even in backlit photography, an adequateexposure is obtained even for the main photographic subject, without thebackground becoming saturated. Moreover, since an appropriate exposureis obtained with a single photographic shot, accordingly it isunnecessary to perform photographic operation for a second time.

Variant Embodiment #1

It would also be possible to arrange to provide an imaging deviceaccording to the embodiment described above to a high-functioningportable telephone or to a tablet terminal. In this case, a camera unitthat is mounted to such a high-functioning portable telephone or to sucha tablet terminal would be built so as to employ a laminated typeimaging element of the above described type.

Variant Embodiment #2

In the embodiment described above, an example was explained in which,during still image photography, when capturing an image to be recordedafter release actuation, the charge accumulation time intervals werecontrolled separately for each of the blocks 131. However, control ofthe charge accumulation time intervals separately for each of the blocks131 is not to be considered as being limited to still image photography;such control could also be performed during photography of a live viewimage, or during movie image photography. For example, if capture of amovie image is being performed, then, when capturing the images ofseveral frames, the charge accumulation time intervals for the framesmay be controlled in units of the blocks 131.

According to this type of variant embodiment #2, it is possible tocontrol the charge accumulation time interval in an appropriate mannerfor each frame, even during photography of a live view image and/or of amovie image.

Variant Embodiment #3

While, in the explanation given above, an example was explained in whichthe charge accumulation time interval was subdivided into 8 stages, itwould also be acceptable to subdivide the charge accumulation timeinterval into 4 stages or into 16 stages, and this number of stages maybe varied as appropriate.

Variant Embodiment #4

In the above explanation, an example was explained in which one greencolored pixel Gr(3,4) in each block 131 was endowed with the function ofacting as a monitoring sensor. However, it would also be acceptable toarrange to provide monitoring sensors that are different from the PDsthat are incorporated in the pixels.

Variant Embodiment #5

In the above explanation, it was arranged for the green colored pixelGr(3,4) that was endowed with the function of acting as a monitoringsensor for the block 131 to have structure in common with other pixelswithin the same block 131. Instead of this it would also be acceptable,for pixels other than the green colored pixel Gr(3,4) that is endowedwith the function of acting as a monitoring sensor, to arrange toperform charge accumulation without separating the charge accumulationtime interval into a plurality of portions from the time point t1 untilthe time point t8, and to continue this charge accumulation until thepixel signal level from the monitoring sensor (i.e. from the greencolored pixel Gr(3,4)) reaches the decision threshold value. In thiscase, for these pixels other than the green colored pixel Gr(3,4) thatis endowed with the function of acting as a monitoring sensor, thereading out during charge accumulation and the addition processingbecomes unnecessary.

Variant Embodiment #6

While an example was explained above in which a green colored pixelGr(3,4) that was positioned at the approximate center of each of theblocks 131 was chosen as the pixel to be endowed with the function ofacting as a monitoring sensor, the position of the position that is tobe made to act as the monitoring sensor should not be considered asbeing limited to a pixel that is in the approximate center of its block;the position of the monitoring pixel within the block 131 may be variedas appropriate.

Variant Embodiment #7

While, in the embodiment described above, an example was explained inwhich a monitoring sensor was provided for each of the blocks 131, itwould also be acceptable to provide some blocks 131 that are notequipped with any such monitoring sensor. In this case, the chargeaccumulation time interval for the pixels of a block that does not haveany monitoring sensor may be determined on the basis of the chargeaccumulation amounts derived by one or a plurality of monitoring sensorsof one or a plurality of neighboring blocks to which one monitor sensoror monitoring sensors are provided. It would be acceptable to arrange todetermine the charge accumulation amount on the basis of the chargeaccumulation amount derived from a monitoring sensor for a singleneighboring block 131; or it would also be acceptable to arrange todetermine the change accumulation amounts on the basis of the chargeaccumulation amounts derived from monitoring sensors for a plurality ofneighboring blocks 131 (for example eight or four blocks around thecorresponding block).

Variant Embodiment #8

In the explanation given above, an example was explained in which thegreen colored pixels Gr were endowed with the function of acting asmonitoring sensors, and were taken as being representative of othercolors such as blue color and red color and so on (the green coloredpixels may be Gr or Gb). Instead of this, it would also be acceptable toarrange for the pixels that are endowed with the function of acting asmonitoring sensors to be provided in some other color. In other words,any of the green colored pixels Gr, the blue colored pixels B, and thered colored pixels R may function as monitoring sensors.

In a variant embodiment #8, on the basis of the charge accumulationamount obtained from a monitoring sensor that consists of a greencolored pixel Gr, the charge accumulation time interval for all of thesame colored (i.e. green colored) pixels Gr and Gb that are included inthis block 131 may be determined. Moreover, on the basis of the chargeaccumulation amount obtained from a monitoring sensor that consists of ablue colored pixel B, the charge accumulation time interval for all ofthe same colored (i.e. blue colored) pixels B that are included in thisblock 131 may be determined. Yet further, on the basis of the chargeaccumulation amount obtained from a monitoring sensor that consists of ared colored pixel R, the charge accumulation time interval for all ofthe same colored (i.e. red colored) pixels R that are included in thisblock 131 may be determined.

The normalization processing in the case of this variant embodiment #8is performed separately for the green colored pixels Gr and Gb, for theblue colored pixels B, and for the red colored pixels R. And, after thisnormalization processing has been performed for each color separately,then adjustment of the pixel signal values between the various colors isperformed as white balance processing.

The above explanation relates only to examples; the present invention isnot to be considered as being limited by the particular structure of anyof the embodiments. Moreover, the structures of the embodiments andvariant embodiments described above may be combined in any appropriatemanner.

The contents of the disclosures of the following applications, uponwhich priority is claimed, are hereby incorporated herein by reference:

Japanese Patent Application 2013-243,946 (filed on 26 Nov. 2013); and

Japanese Patent Application 2014-7,869 (filed on 20 Jan. 2014).

The invention claimed is:
 1. An imaging element comprising: a firstimage capture region including a plurality of pixels; a second imagecapture region including a plurality of pixels, the imaging elementbeing configured to set different image capture conditions in the firstimage capture region and in the second image capture region,respectively; a first pixel that generates a signal to be used forsetting an image capture condition in the first image capture region; asecond pixel that generates a signal to be used for setting an imagecapture condition in the second image capture region; a third pixel thatgenerates a signal to be used for setting the image capture condition inthe first image capture region; and a fourth pixel that generates asignal to be used for setting the image capture condition in the secondimage capture region, wherein the first image capture region includesthe first pixel and the third pixel; the second image capture regionincludes the second pixel and the fourth pixel; the first pixel and thesecond pixel receive light in a first color; the third pixel and thefourth pixel receive light in a second color; the image capturecondition in the first image capture region is set based upon thesignals output from the first pixel and the third pixel at a pluralityof times, and the image capture condition in the second image captureregion is set based upon the signals output from the second pixel andthe fourth pixel at a plurality of times; exposure time in the firstimage capture region is set when, among a signal that is generated byadding the signals output from the first pixel at the plurality of timesand a signal that is generated by adding the signals output from thethird pixel at the plurality of times, one of the signals becomesgreater than a threshold; and exposure time in the second image captureregion is set when, among a signal that is generated by adding thesignals output from the second pixel at the plurality of times and asignal that is generated by adding the signals output from the fourthpixel at the plurality of times, one of the signals becomes greater thanthe threshold.
 2. The imaging element according to claim 1, wherein: thefirst pixel is arranged in a region other than the second image captureregion, and the second pixel is arranged in a region other than thefirst image capture region.
 3. An imaging device comprising the imagingelement according to claim
 1. 4. An imaging element comprising: a firstimage capture region including a plurality of pixels; a second imagecapture region including a plurality of pixels, the imaging elementbeing configured to set different image capture conditions in the firstimage capture region and in the second image capture region,respectively; a first pixel that generates a signal to be used forsetting an image capture condition in the first image capture region; asecond pixel that generates a signal to be used for setting an imagecapture condition in the second image capture region; a third pixel thatgenerates a signal to be used for setting the image capture condition inthe first image capture region; and a fourth pixel that generates asignal to be used for setting the image capture condition in the secondimage capture region, wherein the first image capture region includesthe first pixel and the third pixel; the second image capture regionincludes the second pixel and the fourth pixel; the first pixel and thesecond pixel receive light in a first color; the third pixel and thefourth pixel receive light in a second color; the image capturecondition in the first image capture region is set based upon thesignals output from the first pixel at a plurality of times, and theimage capture condition in the second image capture region is set basedupon the signals output from the second pixel at a plurality of times;exposure time in the first image capture region is set when, among asignal that is generated by adding the signals output from the firstpixel at the plurality of times and a signal that is generated by addingthe signals output from the third pixel at the plurality of times, oneof the signals becomes greater than a threshold; and exposure time inthe second image capture region is set when, among a signal that isgenerated by adding the signals output from the second pixel at theplurality of times and a signal that is generated by adding the signalsoutput from the fourth pixel at the plurality of times, one of thesignals becomes greater than the threshold.
 5. The imaging elementaccording to claim 4, wherein: the first pixel is arranged in a regionother than the second image capture region, and the second pixel isarranged in a region other than the first image capture region.
 6. Animaging device comprising the imaging element according to claim
 4. 7.An imaging element, in which different image capture conditions are ableto be set in each of image capture regions; comprising: a first imagecapture region that captures a subject; a second image capture regionthat generates a signal to be used for determining a setting value ofthe image capture condition in the first image capture region; a thirdimage capture region that captures a subject; and a fourth image captureregion that generates a signal to be used for determining a settingvalue of the image capture condition in the third image capture region;a first pixel that generates a signal to be used for setting an imagecapture condition in the first image capture region; a second pixel thatgenerates a signal to be used for setting an image capture condition inthe second image capture region; a third pixel that generates a signalto be used for setting the image capture condition in the first imagecapture region; and a fourth pixel that generates a signal to be usedfor setting the image capture condition in the second image captureregion, wherein the first image capture region includes the first pixeland the third pixel; the second image capture region includes the secondpixel and the fourth pixel; the first pixel and the second pixel receivelight in a first color; the third pixel and the fourth pixel receivelight in a second color; the image capture condition in the first imagecapture region is set based upon the signals output from the first pixeland the third pixel at a plurality of times, and the image capturecondition in the second image capture region is set based upon thesignals output from the second pixel and the fourth pixel at a pluralityof times; exposure time in the first image capture region is set when,among a signal that is generated by adding the signals output from thefirst pixel at the plurality of times and a signal that is generated byadding the signals output from the third pixel at the plurality oftimes, one of the signals becomes greater than a threshold; and exposuretime in the second image capture region is set when, among a signal thatis generated by adding the signals output from the second pixel at theplurality of times and a signal that is generated by adding the signalsoutput from the fourth pixel at the plurality of times, one of thesignals becomes greater than the threshold.
 8. The imaging elementaccording to claim 7, wherein: the first pixel is arranged in a regionother than the second image capture region, and the second pixel isarranged in a region other than the first image capture region.
 9. Animaging device comprising the imaging element according to claim 7.